TWI439161B - Sequence generating method for efficient detection and method for transmitting and receiving signals using the same - Google Patents

Abstract

Transmitting signals to a receiver by a transmitter in a mobile communication system comprising mapping a sequence generated by using a Zadoff-Chu sequence having a root index to frequency domain indexes, wherein the root index is selected from a predetermined index set comprising a first index, a second index and a third index, wherein a sum of the first index and the second index corresponds to the length of the Zadoff-Chu sequence, and wherein the third index corresponds to a predetermined number, and transmitting the mapped sequence to the receiver. Detecting a sequence used in a received, hereinafter Rx, signal by a receiver in a mobile communication system comprising receiving the Rx signal from a transmitter, and detecting the sequence used in the Rx signal, wherein the sequence used in the Rx signal is generated by using a Zadoff-Chu sequence having a root index selected from a predetermined index set, wherein the predetermined index set comprises a first index, a second index and a third index, wherein a sum of the first index and the second index corresponds to the length of the Zadoff-Chu sequence, and wherein the third index corresponds to a predetermined number.

Description

Sequence generation method for efficient detection and method for transmitting and receiving signals

The present invention relates to a signal transmission/reception method for a telecommunication system according to an orthogonal frequency division multiplexing (OFDM) scheme, and more particularly to a method for allowing a receiving end to efficiently detect a mobile communication system. A sequence generation method of a sequence of a specific channel, and a signal transmission/reception method using the sequence generation method.

The OFDM, OFDMA, and SC-FDMA schemes used in the present invention will be detailed below.

Recently, as the demand for high-speed data transmission has rapidly increased, the OFDM scheme is more advantageous for this high-speed transmission system, and thus the OFDM scheme is used for transmission schemes of various high-speed communication systems.

The OFDM (Orthogonal Frequency Division Multiplexing) scheme will be described below.

OFDM scheme

According to the basic principle of the OFDM scheme, the OFDM scheme divides a high rate data stream into a plurality of slow rate data streams, and simultaneously transmits the slow rate data streams via multiple carriers. Each of these vectors is referred to as a pair of carriers.

In the OFDM scheme, orthogonality exists between multiple carriers. Therefore, although the frequency components of the carriers overlap each other, the overlapping frequency components can be detected by a receiving end.

More specifically, a high rate data stream is converted to a parallel slow rate data stream via a serial to parallel (SP) converter. Individual subcarrier Multiplied by the above parallel data stream, the individual data stream is added to the multiplied result, and the added result is transmitted to the receiving end.

On the other hand, the OFDMA scheme is a multiple access method for allowing an OFDM system to configure a secondary carrier in a total frequency band to each of a plurality of users in accordance with a transmission rate required by each user.

A conventional SC-FDMA (Single Carrier FDMA) scheme will be described below in the description. This SC-FDMA scheme is also known as the DFS-S-OFDM scheme.

SC-FDMA solution

The SC-FDMA scheme will be detailed below. The SC-FDMA scheme, which is mainly applied to the uplink, performs expansion based on the DFT matrix in a frequency domain before generating the OFDM signal, modulates the expansion result according to the conventional OFDM scheme, and transmits the modulated result.

Some variables will be defined below to explain the SC-FDMA scheme. "N" is an indication of the number of subcarriers transmitting the OFDM signal, "Nb" is an indication of the number of subcarriers for a predetermined user, "F" is an indication of a discrete Fourier transform (DFT) matrix, "s" is an indication An indication of a data symbol vector, "x" is an indication of the data dispersion vector in the frequency domain, and "y" is an indication of the OFDM symbol vector transmitted in the time domain.

Before the SC-FDMA scheme transmits the data symbol (s), the data symbol (s) is dispersed, as expressed by Equation 1 below:

In Equation 1, An indication of the N _b size DFT matrix of the data symbol (s) is dispersed.

The secondary carrier mapping procedure is performed on the dispersed vector (x) in accordance with a predetermined secondary carrier configuration technique. The mapping generation signal is converted into a time domain signal by the IDFT module, so as to obtain a desired signal to be transmitted to the receiving end. In this case, the transmission signal converted into the time domain signal by the transmission end can be expressed by the following Equation 2:

In Equation 2, An indication of the N-size IDFT matrix used to convert the frequency domain signal into a time domain signal.

Then, a cyclic prefix is inserted into the signal "y" generated by the above method to transmit the generated signal. This method can generate a transmission signal, and the method of transmitting it to the receiving end is called an SC-FDMA method. The size of the DFT matrix can be controlled in various ways to achieve a particular purpose.

The concept of the above has been revealed based on DFT or IDFT operations. For convenience of explanation, the following description does not disclose the difference between DFT (Discrete Fourier Transform) or FFT (Fast Fourier Transform) schemes.

If the number of input values for the DFT operation is represented by a modulus index of 2, those skilled in the art should be familiar with the DFT operation to replace the FFT operation. In the following description, the FFT operation can also be considered as a DFT operation or other equivalent operation without any change.

An OFDM system typically uses a complex OFDM symbol to form a single frame such that it transmits a single frame of OFDM symbols in a frame unit. OFDM first transmits the preamble at intervals of several frames or frames. In this case, the number of OFDM symbols in the foregoing is based on the system type. And different.

For example, an IEEE 802.16 system based on the OFDM scheme first transmits a single OFDM symbol at the interval of each downlink frame. The prior text is applied to a communication terminal so that the communication terminal can be synchronized with the communication system, can search for a desired cell, and can perform channel estimation.

Figure 1 shows the structure of a downlink subframe under an IEEE 802.16 system. As shown in Figure 1, the previous text consisting of a single OFDM symbol is placed in front of each frame so that it is transmitted earlier than each frame. The foregoing can also be used to search for cells, perform channel estimation, and synchronize in time and frequency.

Figure 2 shows the transmission of the set of sub-carriers from the previous section of the IEEE 802.16 system. Some portions of the sides of a specified bandwidth are used as guard bands. If the number of segments is 3, each segment inserts the sequence into the interval of the three carriers so that the secondary carrier is transmitted to a destination.

The conventional sequence used in the foregoing will be explained as follows. The sequence sequences used in the foregoing are shown in Table 1 below.

The sequence is defined by the number of segments and the value of the IDcell parameter. Each defined sequence is converted to a binary signal in ascending order, and the binary signal is mapped to the secondary carrier by BPSK modulation.

In other words, the hexadecimal series is converted to a binary series (Wk), and the binary series (Wk) is mapped in the range from MSB (most significant bit) to LSB (least significant bit). That is, the value of 0 is mapped to another value of +1, and the value of 1 is mapped to another value of -1. For example, the "Wk" value of the hexadecimal value "C12" at the 0th segment having the index 0 is "110000010010...". The converted binary code values are -1, -1, +1, +1, +1, +1, +1, -1, +1, +1, -1, +1.

The relevant features are maintained in various sequence types that can be composed of binary codes in accordance with the sequence of the prior art. When the data is converted into another data in the time domain, the sequence according to the prior art can maintain a low level of PAPR (spike vs. average power ratio) and is found by computer simulation. If the system structure changes to the other, or applies the sequence to another system, the prior art must search for a new sequence.

Recently, a new sequence for 3GPP LTE (Long-Term Evolution of the Third Generation Partnership Project; here referred to as "LTE") technology has been proposed, and a detailed description thereof will be described below.

Various sequences have been proposed for LTE systems. The sequence for the LTE system will be explained below.

In order to allow the terminal to communicate with the Node B (ie, the base station), the terminal must synchronize with the Node B through a synchronization channel (SCH) and must search for the cell.

The above mentioned operation (in which the terminal synchronizes with the Node B and acquires the ID of a cell including the terminal) is called a cell search program. In general, the cell search system is classified into an initial cell search and an adjacent cell search. The initial cell search procedure is performed when the terminal initial power is turned on. The neighboring cell search system is executed when a connected mode or an idle mode terminal searches for the neighboring node B.

The SCH (synchronous channel) can have a hierarchical structure. For example, the SCH may use a primary SCH (P-SCH) and a primary SCH (S-SCH).

The P-SCH and S-SCH can be included in a radio frame by various methods.

Figures 3 and 4 show various methods for including P-SCH and S-SCH in a radio frame. In each case, the LTE system can configure the SCH according to the structure shown in FIG. 3 or 4.

In FIG. 3, the P-SCH is included in the last OFDM symbol of the first subframe, and the S-SCH is included in the last OFDM symbol of the second subframe (in FIG. 3, a sub The duration of the frame is assumed to be 0.5 milliseconds, but the length of the subframe can be configured differently depending on the system.

In FIG. 4, the P-SCH is included in the last OFDM symbol of the first subframe, and the S-SCH is included in the last second OFDM symbol from the first subframe (in FIG. 4, The duration of a sub-frame is also assumed to have 0.5 milliseconds).

The LTE system can acquire time/frequency synchronization through the P-SCH. And the S-SCH can include a cell group ID, frame synchronization information, antenna configuration information, and the like.

The P-SCH configuration method proposed by the conventional 3GPP LTE system will be explained as follows.

The P-SCH is transmitted through a frequency band of 1.08 MHz based on a carrier frequency and corresponds to 72 subcarriers. In this case, since the LTE system defines 12 subcarriers as a single resource block (RB), the interval among the individual subcarriers is 15 kHz. In this case, 72 pairs of vectors are equal to 6 RB.

The P-SCH system is widely used in communication systems (such as OFDM or SC-FDMA systems) that can use several orthogonal sub-carriers, so that it must satisfy the following first To the fifth condition.

According to the first condition, in order to allow a receiving end to detect an excellent performance, the above-mentioned P-SCH must have excellent autocorrelation and cross-correlation features in the time domain associated with the constituent sequence of the P-SCH.

According to the second condition, the above P-SCH must allow a low complexity associated with the synchronization detection.

According to the third condition, the "best" P-SCH has an Nx repetitive structure to implement an excellent frequency offset estimation performance.

Preferably, the P-SCH has a low PAPR (spike vs. average power ratio) or a low CM, depending on the fourth condition.

According to the fifth condition, if the P-SCH is used for a channel estimation channel, the frequency response of the P-SCH may have a fixed value. In other words, from the perspective of channel estimation, a flat response in the frequency domain that is well known in the art has the best channel estimation performance.

Although various sequences have been proposed by the prior art, the above-described conditions are not sufficiently satisfied by the prior art.

Accordingly, the present invention is directed to a method for generating a sequence for efficient detection, and a method for transmitting/receiving signals, which substantially obviate one or more problems due to limitations and disadvantages of the related art.

It is an object of the present invention to provide a method for providing a sequence having excellent correlation characteristics.

Another object of the present invention is to provide a method for generating one in a transmission end The method of sequence and transmission of the sequence so that the receiving end can easily detect the sequence.

It is still another object of the present invention to provide a method for efficiently detecting the above generated/transmitted signals.

Additional advantages, objects, and features of the invention will be set forth in part in the description. The objectives and other advantages of the invention will be apparent from the description and appended claims appended claims

To achieve these and other advantages and in accordance with the present invention as broadly described herein, a signal transmission method includes selecting a root index included in a root index set such that it comes from having the root index set A first sequence and a second sequence in a plurality of sequences of each of the root indexes can satisfy a conjugate symmetric property; generate a sequence according to the selected root index in a frequency domain or a time domain; and map the generated sequence to a a frequency domain resource component; and converting the frequency domain mapping sequence into a time domain transmission signal and transmitting the time domain transmission signal.

Preferably, the multi-sequence is an indication of a Zadoff-Chu sequence, and the root index set satisfying the conjugate symmetry property allows the sum of the root indices of each of the first and second sequences to correspond to a length of the Zadoff-Chu sequence.

Preferably, the Zadoff-Chu sequence has an odd length, and an equation for generating a Zadoff-Chu sequence is indicated by the following equation:

The length of the Zadoff-Chu sequence is "N", "M" The root index of the Zadoff-Chu sequence, and "n" is the index of each constituent component of a particular Zadoff-Chu sequence.

Preferably, the root index set (where the sum of the individual root indices of the first and second sequences corresponds to the length of the Zadoff-Chu sequence) is set such that the sum of the individual root indices of the first and second sequences is set The value is "N".

Preferably, the length of the Zadoff-Chu sequence is 63, and the root index of the first sequence is set to 34, and the root index of the second sequence is set to 29.

Preferably, the number of the multiple sequences is three, and the root index of a third sequence from the multiple sequences of the root index set is selected in consideration of the influence of a frequency offset.

Preferably, in the root index set, the root index of the first sequence is set to 34, the root index of the second sequence is set to 29, and the root index of the third sequence is set to 25.

Preferably, the multiple sequence is used as a P-SCH (primary SCH) transmission sequence.

Preferably, the multiple sequence is used as an uplink preamble transmission sequence.

In another aspect of the present invention, a signal transmission method is provided, comprising: selecting a root index included in a root index set, such that one of each of the root indexes from the root index set is first And the sum of the individual root indexes of the sequence and the second sequence, corresponding to a length of the multiple sequence; generating the sequence according to the selected root index in a frequency domain or a time domain; mapping the generated sequence to a frequency domain resource element; And converting the frequency domain mapping sequence into a time domain transmission signal and transmitting the time domain transmission signal.

Preferably, the multi-sequence has an indication of an odd length Zadoff-Chu sequence, and the equation for generating the Zadoff-Chu sequence is indicated by the following equation:

Wherein the length of the Zadoff-Chu sequence is "N", and the root index set (where the sum of the individual root indices of the first and second sequences corresponds to the length of the Zadoff-Chu sequence) is set to make the first and second sequences The sum of the individual root indices is set to the value FN", where "M" is the root index of the Zadoff-Chu sequence, and "n" is the index of each constituent component of a particular Zadoff-Chu sequence.

In still another aspect of the present invention, there is provided a method for calculating an interaction correlation value between a received (Rx) signal and each of a plurality of sequences including a first sequence and a second sequence, the method Included: a complex intermediate value generated when calculating the Rx signal and an interaction correlation value from a first sequence of the plurality of sequences; and calculating and subtracting the Rx signal from the intermediate value by adding and subtracting the intermediate value Each of the first sequence of the plurality of sequences, and the respective cross-correlation values between the Rx signal and the second sequence from the plurality of sequences, one for the root index of the first sequence and one for the second The root index of the sequence is set such that the first sequence and the second sequence satisfy the conjugate symmetry property.

Preferably, the first sequence and the second sequence satisfying the conjugate symmetry property satisfy each other in a conjugate complex relationship.

Preferably, the intermediate values include: a first result value indicating an interaction correlation value between a real part of the Rx signal and a real part of the first sequence; and an indication of an imaginary part of the Rx signal and a second result value of an interaction correlation value between one of the imaginary parts of the first sequence; a third result value indicating an interaction correlation value between an imaginary part of the Rx signal and a real part of the first sequence; in The fourth resulting value of the value of the interaction between the real part of the Rx signal and the imaginary part of one of the first sequences.

Preferably, the cross-correlation value between the Rx signal and the first sequence is calculated such that the sum of the first result value and the second result value is a real part, and the difference between the third result value and the fourth result value is a virtual unit.

Preferably, the cross-correlation value between the Rx signal and the second sequence is calculated such that the difference between the first result value and the second result value is a real part, and the sum of the third result value and the fourth result value is a virtual unit.

In still another aspect of the present invention, a signal transmission method using a fixed amplitude zero autocorrelation (CAZAC) sequence is provided, comprising: selecting a predetermined root index, and according to the selected root index in a frequency domain or a time domain Generating a CAZAC sequence; continuously mapping the generated CAZAC sequence to a frequency domain resource element; and converting the frequency domain mapping sequence into a time domain transmission signal, and transmitting the time domain transmission signal, wherein the time domain transmission signal is in a correspondence The specific component of the portion from the frequency "0" of the CAZAC sequence is omitted, so that the generated time domain transmission signal does not have a component corresponding to the frequency "0".

Preferably, the time domain transmission signal is transmitted after passing through a component corresponding to a portion of the frequency "0" from the CAZAC sequence.

Preferably, the CAZAC sequence has an odd length Zadoff-Chu sequence, and an equation for generating a Zadoff-Chu sequence is indicated by the following equation:

The length of the Zadoff-Chu sequence is "N", "M" is the root index of the Zadoff-Chu sequence, and "n" is the index of each component of a specific Zadoff-Chu sequence.

Preferably, the length of the Zadoff-Chu sequence is 63, and in the Zadoff-Chu sequence, the constituent components corresponding to the "n" value of "0 to 30" (ie, n=0 to 30) are continuously mapped to the frequency. The resource element is from a frequency resource element having a frequency resource element index of "-31" to a frequency resource element having a frequency resource element index of "-1"; and the composition corresponds to "32 to 62" (ie, n= The components of the "n" value of 32 to 62) are continuously mapped to the frequency resource elements, from a frequency resource element having a frequency resource element index of "1" to a frequency resource element having a frequency resource element index of "31". .

Preferably, the Zadoff-Chu sequence is used as a P-SCH (primary SCH) transmission sequence.

The foregoing description of the preferred embodiments of the invention and the claims

DETAILED DESCRIPTION OF THE INVENTION Reference will now be made in detail to the preferred embodiments embodiments The same reference numbers will be used throughout the drawings to refer to the same or similar parts.

The detailed description below discloses various specific embodiments and modifications of the invention. In some cases, in order to prevent the ambiguity concept of the present invention, it is well known to those skilled in the art. The device or device will be omitted and indicated in block diagram form in accordance with important functions of the present invention.

It should be noted that the present invention generates and transmits a sequence such that the receiving end can efficiently receive or detect a corresponding sequence. To this end, the present invention provides various methods for generating/transmitting a sequence for use in a particular channel, for example, a method for generating a sequence in a time or frequency domain, a method in the time or frequency domain a method of mapping a generated sequence to a frequency domain sequence, a method for converting a frequency domain sequence into a time domain sequence, a data processing method for removing or avoiding a DC component, and a method for A method of generating a sequence of iterative or repeated features in the domain, and the like.

Basic embodiment

The sequence generated by the present invention can be applied to various channels.

For example, the sequence can be applied to an uplink preamble transmission signal (such as a random access channel (RACH)) or a downlink synchronization channel or the like. Moreover, the sequence can be applied to a data channel or a channel for a control signal, and can also be applied to a synchronization channel that allows time or frequency synchronization procedures.

For ease of description, although the present invention will describe a method of generating a sequence for a synchronization channel (e.g., a P-SCH channel), it should be noted that the scope of the present invention is not limited to the following examples only, and may be applied to other examples. .

For example, in the case of transmitting specific information through a corresponding channel that does not establish time synchronization, the instantaneous correlation output data of the time synchronization concept described above is used to obtain corresponding information. If the zero-delay-related output function is executed, the specific information is followed by the same procedure.

Figure 5 is a diagram showing the transmission used to implement one embodiment of the present invention / Block diagram of the receiving end.

The transmission side will be explained below with reference to Figure 5. When receiving the input data 501, the output performs a channel encoding 502 for adding redundant bits (also referred to as complex redundant bits) to the input data 501 so that the input data 501 can be prevented from being distorted in one channel.

The channel coding unit 502 can be implemented by an acceleration code or an LDPC code or the like. The channel coding unit 502 can be omitted from a procedure for transmitting a synchronization channel or an uplink channel. Thus, the channel coding unit 502 is not a necessary component of the present invention for providing a sequence generation method for a synchronization channel, or for transmitting a method of the uplink preamble.

Thereafter, a data input mapping unit 504 is generated, which may be implemented with QPSK or 16QAM or the like. Then, the mapped symbol signal is carried on the time domain carrier via the IFFT 505, and the output signal of the IFFT 505 is transmitted to a radio frequency (RF) channel via the filter 506 and the DAC (digital to analog converter) 507. The operation of the receiving end is performed in the reverse order of the operation of the transmitting end.

Fig. 5 is not an example structure of a transmission end implementing a sequence generation/transmission method which will be described later.

Figure 6 is a flow chart illustrating the basic concept of a generation/transmission sequence in accordance with an embodiment of the present invention.

Referring to Fig. 6, the sequence generation method produces a sequence having a length N in the time or frequency domain in step S101. In step S101, a specific embodiment of the invention proposes selecting a root index in the root index set, the root index set enabling the at least two sequences having the index in the root index set to conform to the "conjugate symmetry property". By using the sequence with an index that satisfies the conjugate symmetry properties, The receiving end can easily detect the received signal by a related operation. The conjugate symmetry properties and other features of this particular embodiment are described below.

On the other hand, if the sequence is generated in the time domain, the sequence generation method performs an N-point FFT operation, so the sequence is mapped to a frequency domain resource element. It should be noted, however, that the invention is not limited to sequence generation in the time domain and can be implemented for generating sequences in the frequency domain. Thus, for a particular embodiment for generating a sequence in the frequency domain, the FFT or DFT steps can be omitted.

Meanwhile, according to the requirements of a communication system, the sequence generation method may perform processing of the DC (Direct Current) component and insertion of the protection secondary carrier at step S105. In step S105, the processing DC component is used to prevent the generated sequence from having a DC component in the frequency domain. It can be done by directly penetrating the DC component or any other equivalent operation from the sequence.

The PAPR attenuation technique may be applied to the generation sequence at step S107 as needed, and a corresponding sequence is converted into a time domain sequence by an IDFT or IFT (Inverse Fourier Transform) operation at step S109. As described above, those skilled in the art will appreciate that DFT or FFT can be selectively performed in accordance with the value of N.

The sequence generated and/or transmitted by the above scheme may be an uplink preamble, a downlink synchronization channel signal or any other equivalent signal.

The sequence generation method and signal transmission method according to the present invention will be described in more detail below.

If a sequence of N length is generated at step S101, the sequence may be selected in a set of indices having multiple indices for distinguishing in the sequence, so that it may be generated by the selected index.

In this case (as described above), one embodiment of the present invention provides A method for generating a sequence by selecting an index in an index set, wherein at least two indices of the indices satisfy a conjugate symmetry property. In this case, the conjugated symmetric property indicates a sequence corresponding to a particular index, which is equal to the conjugate complex number of another sequence corresponding to another sequence, and the details thereof will be described with reference to the sequence details detailed below.

In the case of using at least one sequence of multiple sequences, each of which includes an index satisfying the conjugate symmetry property, the receiving end can significantly reduce the number of cross-correlation calculations, so that it can easily detect the desired signal.

The present invention provides a method for omitting a component corresponding to a DC secondary carrier (as shown in S105) and transmitting the generated signal.

The individual steps of Figure 6 will be detailed below.

First, a step S101 for forming/generating a sequence having an N length will be described hereinafter.

In accordance with an embodiment of the present invention, the present invention not only provides a method for correlating features of sequence expression, but also provides a method for generating a sequence capable of maintaining a predetermined amplitude. For this purpose, this particular embodiment produces a sequence of a particular length in the time or frequency domain.

Preferred conditions required for the sequence of this embodiment will be described below.

As described above, in order to increase the efficiency of the amplifier at the transmitting end, it is preferable that the transmitting end transmits a sequence for reducing the PAPR. The sequence according to this embodiment may have a predetermined amplitude value in the time domain. Preferably, the signal amplitude of the sequence varies slightly not only in the time domain but also in the frequency domain.

When most communication methods have configured a predetermined frequency band to a specific transmission At the receiving end, the communication method has limited a maximum power value that can be used at the configured frequency band. In other words, the general communication method includes a specific spectral mask. Thus, although a fixed amplitude sequence is transmitted in the time domain, if the signal amplitude is irregular in the frequency domain, the signal may unpredictably exceed the spectral mask when the sequence begins in the frequency domain.

If the channel value is pre-cognized in the frequency domain, it is preferable that the system can perform power configuration according to different methods according to the good or bad state of the channel. However, since the system is difficult to recognize the channel in advance due to the characteristics of the foregoing usage, the power of the sub-carrier used is substantially fixed.

Regarding the frequency flat feature described above, in the case where a corresponding sequence is used as a specific channel to perform channel estimation (if the P-SCH is used in an LTE system), it is determined that one of the channel estimation reference signals may have a frequency. The best case of flat features.

In addition to the PAPR features described above, sequences in accordance with the present embodiments may have superior correlation features to facilitate detection or differentiation of signals. Excellent interaction-related features indicate the emergence of superior autocorrelation features and the emergence of superior interactivity-related features.

Preferably, the sequence can be generated by the transmitting end so that the receiving end can easily acquire synchronization. Synchronization as described above may refer to frequency synchronization and time synchronization. In general, if a particular mode is repeated in a single OFDM symbol in the time domain, the receiving end can easily obtain frequency synchronization and time synchronization.

Thus, a sequence in accordance with the present embodiment can be established such that a particular sequence is repeated within a single OFDM symbol in the time domain, but it is not necessary. Hereinafter, an unrestricted description for generating a sequence having a repeated structure will be explained Sexual examples. For example, in the sequence generation step, the system can insert a preamble sequence that is provided with two identical patterns in a single OFDM symbol generated by the N-point FFT module. There is no limitation on the method for constructing a sequence of a specific length by repeating the same pattern in the time domain.

If the N-point FFT or DFT encounters a serious problem, a sequence of length N/2 is generated and repeated twice, and then a sequence with a total length N can be configured. If a sequence of length N/4 is generated and repeated twice, and the repeated sequence is inserted, a preamble sequence of total length N/2 can be configured. The N/2 preamble sequence may have a length of N/2 in the frequency domain. In this case, the sequence spacing is adjusted in the frequency domain such that a sequence of length N can be produced.

At the same time (as described above), the present invention may also use a non-repetitive sequence in the time domain. In this case, the above repeated operation may be omitted as needed. In other words, the present invention can also generate N-length sequences in the time domain or directly in the frequency domain without repeating the N-length sequence. The sequence used for this step may be a CAZAC sequence, a Golay sequence, or a binary sequence, and the like.

According to this specific embodiment, there are various sequences that can be selected in consideration of the conditions described above. As an exemplary embodiment, the invention proposes to use a CAZAC sequence. In more detail, although a method for forming a sequence having a length of 1024 in the time domain of the CAZAC sequence and inserting the same sequence will be described below, it should be noted that the length of the CAZAC sequence may not be limited to this exemplary method.

According to the CAZAC sequence generated by this specific embodiment, a root index set for distinguishing among available CAZAC sequences is pre-generated, and a specific root index from the generated root index set is selected and generated according to the selected index. the sequence of. In this case, it is preferred that the root index selected for the sequence is selected in the root index set that satisfies the conjugate symmetry property.

In order to satisfy the conjugate symmetry property in the CAZAC sequence described above, the sum from the two indices in the index set may have different conditions depending on the specific information indicating whether the sequence length is indicated by an even or odd length. The conjugate symmetry property described above can be satisfied if the corresponding sequence length is indicated by an odd length and the sum of the two source indices corresponds to a period (in some cases, the sequence length) of the equation that produces the corresponding sequence.

However, the equations described above for generating corresponding sequences can be changed from one basic formatting equation to another for a particular purpose. In this case, the conditions for satisfying the above-described conjugate symmetry property may be changed to another condition. Indeed, the sum of the two indices must correspond to the period of the equation that can generally produce a corresponding sequence. With regard to this need, a detailed description of a sequence generation method in accordance with the present invention will be described below along with other specific embodiments applied to a particular sequence.

Sequences in accordance with the present invention may be generated in the time and/or frequency domain in accordance with the same principles. For ease of description, the following specific embodiments will be disclosed based on a specific example that generates sequences in the time domain and converts the generated sequences into frequency domain sequences, as examples of generating sequences directly in the frequency domain can be easily understood (due to their Only some of the steps of a particular embodiment for generating a sequence in the time domain are omitted. However, it should be noted that the scope of the invention is not limited to the examples and may be applied to other examples as needed.

The following description will reveal a specific example shown in Equation 3 below.

[Equation 3] When N is even, When N is an odd number,

In the example shown in Equation 3, "M" is set to "1" (where "M" is a natural number relative to the prime number of the "N" system), and a CAZAC having a length of 1024 is generated and inserted. (Fixed amplitude zero autocorrelation) sequence. This CAZAC sequence has been disclosed in "Polyphase Codes with Good Periodic Correlation Properties" by David C. Chu in July 1972, Information Theory IEEE Transaction, Volume 18, 4 Edition, pp. 531-532.

In Equation 3, "n" is 0, 1, 2, ..., N-1. Therefore, "N" corresponds to the length of the sequence or the "equivalent sequence length". The reason why N can be expressed as the equivalent sequence length (as described above) is that the generated sequence can have a different length from N in a particular case. For example, the sequence can be generated by any alternative equation for preventing the sequence from having a DC component. Avoiding the DC component of the sequence can be implemented by directly performing a DC component in the frequency domain, but (or) the sequence can be generated by omitting an "n" value corresponding to the DC component. In this case, the length of the generated sequence can be "N-1", not "N". However, this is a special case, and usually "N" corresponds to the length of the sequence. And even in this particular case, "N" corresponds to the substantially sequence length or sequence generation period.

Meanwhile, if the sequence length is predetermined, the present invention can use either of the two equations shown in Equation 3 depending on whether the corresponding sequence has specific information of an even length or an odd length.

As described above, a particular mode that can be used with this particular embodiment can be repeated such that the CAZAC sequence can repeat the particular mode by adjusting the N value. In other words, in Equation 3, the CAZAC sequence is generated and repeated twice under the condition that the "M" value is set to "1" and the "N" value is set to "512", so that a length of 1024 can be generated. the sequence of.

Figure 7 shows the autocorrelation characteristics of the CAZAC sequence in accordance with the present invention.

As described above, the sequences according to this embodiment may have excellent correlation characteristics. The autocorrelation feature of the time domain associated with the CAZAC sequence can be recognized and can have ideal autocorrelation features, as shown in FIG. In summary, the above described CAZAC sequence is an example of a sequence that satisfies the various conditions required for this particular embodiment.

As an optional step in accordance with this embodiment, the steps of mapping the time domain generation sequence to the frequency domain will be detailed below.

According to a method for converting a time domain sequence into a frequency domain sequence according to a predetermined standard of an OFDM system, the N-point FFT program can be performed on an N-length sequence generated in the time domain, as represented by Equation 4 below, such that N The length sequence can be converted into a frequency domain sequence.

In Equation 4, "k" is 0, 1, 2, ..., N-1.

As described above, the time domain sequence generated in the time domain can be converted into the frequency domain sequence " A _k ", as expressed by Equation 4. Additionally, for a particular embodiment for generating sequences in the frequency domain, the frequency domain generation sequence needs to be mapped to frequency resource elements by equivalent operations.

In the case where a CAZAC sequence is used in this particular embodiment, it is preferred that the present invention can continuously map the generated sequence to a frequency domain resource element such that the system can maintain the CAZAC sequence property when the sequence is mapped to the frequency domain resource. Internally, a predetermined amplitude characteristic is maintained in the time domain (or in the frequency domain).

In some embodiments of the invention, the sequence is 2x repeated in the time domain, thus generating a sequence mapping to the frequency domain. In this case, each sequence component in the frequency domain is mapped to every two subcarriers. It has been hypothesized that the term "continuous mapping" in the present invention indicates that the sequence is mapped to a particular number of secondary carriers that are continuously included in the frequency domain, and that includes continuously mapping the sequence to every two secondary carriers.

The step S105 of processing the DC sub-carrier and inserting the protection sub-carrier according to an embodiment of the present invention will be described below with reference to FIG.

In general, a particular OFDM communication method may request processing of a DC secondary carrier and insertion of a fixed protection secondary carrier. If the DC secondary carrier and the protection secondary carrier have to be inserted to meet predetermined criteria for a particular OFDM communication method, then the above step S105 can be performed.

The processing of the DC frequency subcarrier indication data "0" described above is inserted into the subcarrier having the frequency "0" in the frequency domain to solve the DC offset problem encountered in the RF unit of the transmission/reception unit. This operation is equal to running through the DC component.

Not only the above method for inserting the data "0" into the sub-carrier having the frequency "0", but also other methods for obtaining the same effect can be used as needed.

For example, the component to be mapped to the DC subcarrier may be omitted in the sequence generation step S101, so that a generation sequence having no mapping component may be generated. Thereafter, during the step S109 for converting the generated sequence into the time domain sequence, the sequence components corresponding to the DC secondary carrier may be omitted.

Therefore, if a component corresponding to a DC component having a frequency "0" in the frequency domain is removed from a signal transmitted to the time domain, and a sequence having no DC component is transmitted to a destination, many methods are available.

Additionally, a protection secondary carrier insertion indication can be inserted into the protection secondary carrier to reduce adjacent channel interference (ACI).

According to the present invention, when a corresponding signal is mapped to a sub-carrier in the frequency domain, the position of the sub-carrier of the corresponding signal can be configured in the reverse order as needed. For example, the signal is cyclically offset as long as the distance of at least one carrier, and then its mapping procedure is performed.

The present invention may also include a random mapping procedure, however, it is preferred that the location in the frequency domain does not change to another location. Particular embodiments of the present invention will disclose a particular case in which the frequency domain location of the generated signal has not changed to another location.

Next, as an optional step, the PAPR attenuation technique will be applied in detail to step S107 of generating a sequence generated by the above steps in accordance with the present invention.

As described above, the time domain signal is modified by the processing DC to become another signal and inserted into the protection secondary carrier, so the PAPR can be increased.

This embodiment may further implement PAPR fading techniques to reduce the increased PAPR, however, this procedure is not always necessary for the present invention. In this way, during the PAPR attenuation technique, it is preferred that the specific embodiment can make the frequency domain serial code The variation in the amplitude level is minimized and the PAPR attenuation technique can be applied to the frequency domain sequence code at the same time.

The frequency domain sequence is generated by a specific value that is known in advance by the transmission/reception end, so that it can also serve as a reference signal for other usages such as channel estimation.

According to the specific embodiment shown in Fig. 6, the step S109 for converting the above described sequence into a time domain sequence by an IFFT operation will be described below.

The above step S109 is used to generate the last time domain preamble sequence, and is implemented as expressed by the following Equation 5. In this case, the generated sequence can be used to perform synchronization, detect signals, or distinguish between signals.

Preferably, a DC component is omitted from the frequency domain of the signal generated by the conversion of the time domain signal at step S109. By doing so, the time/frequency duality of the CAZAC sequence can be maintained.

The foregoing embodiments have disclosed the above-described methods for generating sequences in the time domain and converting time domain sequences into frequency domain sequences, however, it should be noted that the scope of the sequences of the present invention is not limited to the above-described sequences in the time domain. And also applied to other examples. In other words, it is well known to those skilled in the art that CAZAC sequences (such as Zadoff-Chu sequences) generated in the frequency domain can be directly mapped to frequency domain resource elements.

Specific embodiment based on Frank sequence

Hereinafter, a method for applying any of the above-described CAZAC sequences to a 3GPP LTE system (hereinafter referred to as "LTE") according to the present invention will be described. The method of P-SCH.

In more detail, after repeating the Franconian sequence from the time domain CAZAC sequence, this embodiment of the present invention can generate a P-SCH by processing the data in the frequency domain, and a detailed description thereof will be described hereinafter.

The Frank sequence is a representative example of the CAZAC sequence described above, and includes a fixed amplitude (i.e., a fixed envelope) in the time and frequency domains. The Frankish sequence has an ideal autocorrelation feature, and a representative flange sequence has been disclosed in "Phase shlft pulse codes with good periodic correlation properties" proposed by RLFrank and SAZadoff in 1962. ), IRE Trans. Inform. Theory, IT-8, pp. 381-382.

Meanwhile, if the P-SCH and the S-SCH are multiplexed in the LTE according to the FDM scheme, a method of constructing the P-SCH using the Frank sequence has been previously discussed by the relevant developer.

However, the inventive method proposed by the present invention multiplexes P-SCH and S-SCH according to the TDM scheme, and thus implements an improved P-SCH that is superior to the conventional P-SCH.

Second, a comparison between the conventional P-SCH construction method and the P-SCH construction method of the present invention will be described in detail below.

Equation 6 below can be used to represent the Frankish sequence:

In Equation 6, l _k is shown in Equation 7:

In Equations 6 and 7, "N" refers to the length of the Franck sequence and must satisfy the condition of N = m ² . Further, "r" is a natural number, which is a relative prime number of "m" and smaller than the value of "m".

For example, if N=4, the sequence shown in Equation 6 has a cluster map such as QPSK. If N = 16, the sequence described above shown in Equation 6 has a cluster map such as QPSK. If N=16 and r=1, the generation of the Franconian sequence in the time domain is shown in Table 2 below, and the sequence sequence converted into the frequency domain data is shown in Appearance 3:

The results shown in Table 2 are equal to the QPSK modulation results, and the results in Table 3 have a fixed amplitude.

For example, in the case where the results of Table 3 are used under the condition that the number of sub-carriers 16 is actually used, the system can use 16 sub-carriers with or without the expandable bandwidth.

When the time point acquisition according to the interaction correlation method is implemented in the time domain, if the target data is converted into another data by the BPSK or M-PSK scheme, the complexity of calculating a correlation value is lowered. In this case, the BPSK or M-PSK scheme implements phase rotation on the cluster map to contain the required information. In other words, the present invention uses a simple symbol converter (rather than a complex operation) to calculate correlation values based on a simple complex addition, thus reducing computational complexity.

Moreover, the Frank sequence is an indication of the CAZAC sequence, so it has excellent correlation characteristics in all time and frequency domains.

The Frank sequence has a fixed value in all time and frequency domains, so it has a low PAPR. If a Franck sequence is used to perform channel estimation, the best conditions are provided.

For example, if the signal vector "r" received from the time domain at N=16 and r=1 is represented by r[r(0) r(1)...r(15)], it is used to calculate the signal vector. "r" (r=[r(0) r(1)...r(15)])) and the well-known signal "a" (a=[a(0) a(1)...a( 15) The equation for the correlation between ^H ]) and the signal vector can be expressed by Equation 8: [Equation 8] R(d) = r. a

In Equation 8, "a" is shown in Table 2 above.

If the R(a) value is directly calculated by Equation 8, a complex multiplication of 15 and a complex addition of 15 are required to calculate a single value "R(d)".

However, due to the unique nature of the Frank sequence "a", the present invention can change the code of the real or imaginary part of an Rx signal to be multiplied by another code, and the addition can be performed using the modified code to calculate the correlation value. Thus, the present invention can perform the above calculations in addition to complex multiplication using only 15 complex additions.

Typically, the complexity of a single complex multiplication operation is about 8 times higher than a single complex addition operation.

This pre-proposed method configures the P-SCH using the advantages of the Franck sequence. In other words, it has been proposed to use an FDM-based P-SCH having a flange sequence of 16 lengths mapped to 64 subcarriers.

Figure 8 is a conceptual diagram illustrating a method for constructing a P-SCH in accordance with the present invention.

Referring to Fig. 8, a flange sequence having a length of 16 is inserted into the frequency domain at intervals of the 2 frequency index. In other words, the sequence of Table 3 is inserted into the frequency domain at the interval between the two frequency indices. In this case, the interval between the two frequency indices indicates that the mth sequence is inserted into the kth subcarrier, the unordered sequence is inserted into the (k+1)th subcarrier, and the (m+1)th sequence is inserted into the (k+2)th subcarrier. .

Inserting the above sequence in the frequency domain at intervals of two frequency indices After copying in the frequency domain and then extending, other sequences mapped to Figure 8 of a total of 64 sub-carriers are available. The sequence of Figure 8 is inserted into the time domain at intervals of two samples and is then repeated twice.

The present invention can improve the P-SCH configuration described above in the following aspects.

First, the sequence based on the pre-recommended P-SCH construction method includes a specific value having a value of "0" in the time domain, so that the PAPR feature is greatly degraded. The present invention can improve the degradation of PARR characteristics.

The pre-suggested method inserts the sequence into the odd-numbered sub-vector instead of the even-numbered sub-vector to solve the problem caused by the DC carrier (i.e., the 0th sub-carrier). That is, the pre-suggested method inserts data into a secondary carrier having an odd frequency index.

If the sequence generated in the above scheme is observed in the time domain, the QPSK format (i.e., the advantage of the Frank sequence) in the time domain is inevitably changed to another format, resulting in serious problems. The object of the present invention is to solve the above mentioned problems.

Figure 9 is a flow diagram of a method for generating a P-SCH in accordance with the present invention.

Steps S1701 to S1705 of Fig. 9 will be described below with reference to other drawings.

Figure 10 is a conceptual diagram illustrating an exemplary secondary carrier, each mapped to a P-SCH based on an LTE standard.

The P-SCH based on the LTE standard is mapped to 73 sub-carriers (including DC sub-carriers) based on the DC sub-carrier.

This particular embodiment provides a 2x repeated sequence structure in the time domain (i.e., the sequence is repeated twice in the time domain) such that it can be generated by the LTE standard. 73 subcarriers (including DC subcarriers). That is, the present invention provides a sequence having a 2x repetitive structure in the time domain.

After the DC secondary carrier has been processed, the system uses a flange sequence having a length of 71 from a flange sequence having a length of 72 (not shown in Figure 10).

In this case, it is preferred that the 2x repeat sequence in the time domain be set to a Frank sequence. Preferably, the length of the Frank sequence is set to 36, and the variable "r" in Equation 6 is set to "1". If the length of the Frank sequence is set to 36, the Frank sequence has a cluster map such as 6-PSK.

The reason why the length of the Frank sequence is set to 36 is to construct a sequence of destinations to be mapped to 73 pairs of carriers. In other words, if the sequence is generated by two repetitions of the 36 length sequence, the generated sequence can satisfy the LTE standard.

Needless to say, the present invention may choose another sequence of lengths of 64 associated with the LTE system if the repeated format is not required. If the P-SCH is generated by four repetitions of the sequence, a flange sequence having a length of 16 can also be used.

Step S1701 of Fig. 9 will be described in detail below.

Referring to Figure 9, a flange sequence having a length of N _pre = 36 is produced. In this case, "N _pre " is an indication of the length of the initial sequence of P-SCHs. In this case, it is preferable that the variable "r" in Equation 6 is set to "1".

Figure 11 is a block diagram showing a sequence of flanges having a length of 36 in the time domain in accordance with the present invention.

The sequence of Fig. 11 can be expressed as a(i), i = 0, 1, ..., 35. Table 4 below shows the actual value of the above value "a(i)".

Next, step S1702 will be described in detail below.

In the case of a Franck sequence having a length of 36, this sequence is repeated twice in the time domain to produce the generated sequence.

Figure 12 is a block diagram illustrating a 2x repeating sequence in the time domain such that a generating sequence having a length of 72 is produced in accordance with the present invention.

Some of the 2x repeated signals in Figure 12 are shown in Table 5 below:

The sequence values shown in Table 5 are indicative of time domain values.

Next, step S1703 will be described in detail below.

A flange sequence having a length of 72 (i.e., a 2x repetition sequence in the time domain) is generated at step S1702 to be converted into a frequency domain signal by a 72-point FFT or DFT. In this case, from the perspective of the frequency domain, the 2x repetition is implemented in the time domain. Therefore, it is considered to have performed alternate insertions from the even frequency index in the frequency domain. That is, the sequence is inserted into the even-numbered frequency index as shown in FIG. Fig. 13 shows the result of the above step S1703 of Fig. 9.

Some portions of the sequence inserted into the even frequency index can be represented by Table 6 below:

Next, step S1704 will be described in detail below.

This step S1704 is adapted to solve the problem caused by the DC secondary carrier. If the DC subcarrier portion of the communication standard to be used is not used (i.e., if the value of 0 is to be transmitted through the DC subcarrier), then step S1704 is preferably performed.

The present invention provides two methods of solving the DC subcarrier problem described above. For ease of explanation and better understanding of the present invention, step S1704-1 will be described in detail first, and step S1704-2 will be described in detail.

Step S1704-1 is adapted to perform the penetration of a corresponding sequence at the DC secondary carrier. In other words, the term "through" indicates that the corresponding sequence is zeroed out with a value of "0".

Figure 14 shows the result of step S1704-1.

If step S1704-1 is performed on the result of FIG. 13, the first 14 results.

Some parts of the results of Figure 14 can be represented by Table 7 below:

Next, step S1704-2 will be explained below.

Step S1704-2 is adapted to perform mapping in addition to the corresponding sequence of DC subcarriers.

The 2x repeat sequence is made at step S1702 above. Therefore, the result of step S1703 is configured in a specific sequence format, which is inserted into the frequency domain at intervals of the two frequency indices. In other words, it should be noted that the sequence is inserted into the even frequency index.

In this case, the present invention performs step S1704-2 so that the sequence system CS (cyclic offset) processing has been generated to the right or left side.

Fig. 15 shows the right side of the results of the CS results to the 13th chart according to the present invention. Some parts of the results of Figure 15 can be represented by Table 8 below:

If the above step S1704-1 is compared with another step S1704-2, it can be recognized that step S1704-1 is better than step S1704-2.

Step S1704-1 can easily calculate the correlation value using the known signals of Table 5. A detailed method for calculating the correlation value will be described below.

Since the sequence is inserted at the odd-numbered index at step S1704-2, the time-domain sequence value is changed to the other, so that the present invention is difficult to calculate the correlation value using a simple calculation because the sequence value has been changed.

Needless to say, the receiving end moves the carrier frequency from one current position to another by the sub-carrier spacing between the sub-carriers, and can receive the generated signal. However, the first sub-carrier acts as a DC component, so it inevitably encounters a DC offset. As a result, step S1704-1 is superior to step S1704-2 in view of the DC offset problem. - Needless to say, after the receiving action described above, a particular complex multiplication is performed in the time domain and the frequency offset can be carried out subsequently. However, if the multiplication of a particular complex is adapted to calculate a simple correlation value, the efficiency may be excessively degraded.

Next, step S1705 will be described below. Step S1705 is used as an additional step for a particular case where the receiving end does not perform downsampling and is applied to the 128 point FFT program.

The above step S1705 can be used efficiently when the receiving end does not support the downsampling function.

For example, the sub-carrier spacing between the sub-carriers of the LTE system is 15 KHz. If a 128-point FFT (or 128-point DFT) is applied to the LTE system, 128 sample values occur in the time domain, and the 128-point sample value can have a sampling frequency of 1.9 MHz. The receiving end filters the Rx signal (ie, the received signal) at a frequency of 1.08 MHz, and can select any of the following operations (ie, the first and second operations).

According to the first operation, the receiving end uses a sampling frequency of 1.92 MHz without any change. According to the second operation, the receiving end performs downsampling using a sampling frequency of 1.08 MHz and uses a downsampling result.

Step S1705 serves as an additional step for the specific case where the receiving end does not perform the downsampling procedure and uses the frequency of 1.92 MHz without any change.

If an upsampling procedure is required, step S1705 performs upsampling of the sequence generated at a frequency of 1.08 MHz (corresponding to 72 samples) such that the sequence having the frequency of 1.08 MHz is upsampled to another frequency of 1.92 MHz. The digital sampling method basically inserts the value of "0" into 56 subcarriers (56 = 128-72), and performs a 128-point IFFT procedure on the above zero padding result.

A detailed sampling technique is well known to those skilled in the art, and thus its detailed description will be omitted. For reference, the sequence of Table 7 or 8 should be used during a transmission procedure in a corresponding frequency band (i.e., a frequency band of 1.08 MHz).

The operation of the receiving end received by the P-SCH sequence will be detailed below. The interaction related method for use in the receiving end will be explained below.

The example described above shows a 2x overlap structure in the time domain. Therefore, the predetermined range of the Rx signal is determined according to the autocorrelation scheme, and then the cross-correlation scheme is applied to the determined range, so that the fine synchronization acquisition procedure can be implemented.

The method for determining a predetermined range of Rx signals repeated by the autocorrelation scheme is the same as the conventional method for the prior art. Therefore, a method for reducing the number of calculations based on the autocorrelation scheme will be as follows description.

The time point acquisition method based on the interaction correlation scheme can be expressed by the following Equation 9:

In Equation 9, p ( n ) is an indication of the known P-SCH sequence value in the time domain, r ( n ) is an indication of the Rx signal, and M is used to indicate the "M" value of the partial correlation method, N _fft FFT size, and It is an indication of the position at which the time is detected.

If the P-SCH does not have a repeat mode and the maximum frequency offset at the 2 GHz band is 5 ppm, the system can have sufficient performance at M = 1 of Equation 9. Therefore, the present invention does not require the application of some related methods to repeat intervals.

Based on Equation 9, the LTE system performs a downsampling of the Rx signal (ie, 72 samples) using a sampling frequency of 1.08 MHz, and the P-SCH has two symbols in the term of 10 milliseconds.

Therefore, if the time synchronization is obtained by averaging the 5 millisecond term, the computational complexity for time point acquisition can be expressed by Equation 10 below: [Equation 10] (72 complex multiplication + 72 complex addition + 2 complex square operation) *9600

To explain the method for calculating the correlation value according to the present invention, the flange sequence shown in Table 4 is described as an example.

If the Rx signal is indicated by r=[r(0) r(1) r(2), ..., r(35)], the method for calculating the correlation value of the Rx symbol and Table 4 can be used as follows. Parallel procedures are implemented.

First, the real value can be represented by Equation 11 below, and the imaginary value can be implemented as represented by Equation 12 below: [Equation 11] Real: Real[r(0)]-Real[r(2)]+Real[r(5)]+Real[r(8)]+Real[r(11)]+Real[r(13)]-Real[r(14) ]+Real[r(15)]-Real[r(16)]+Real[r(17)]-Real[r(18)]+Real[r(20)]+Real[r(23)]-Real[r( 26)]+Real[r(29)]+Real[r(31)]+Real[r(32)]+Real[r(33)]+Real[r(34)]+Real[r(35)]+cos(pi/3 )*{-Real[r(1)]-Real[r(3)]+Real[r(4)]+Real[r(6)]-Real[r(7)]-Real[r(9)]- Real[r(10)]-Real[r(12)]-Real[r(19)]-Real[r(21)]-Real[r(22)]-Real[r(24)]-Real[ r(25)]-Real[r(27)]+Real[r(28)]+Real[r(30)]}+sin(pi/3)*{-Imag[r(1)]+Imag[r(3) ]+Imag[r(4)]-Imag[r(6)]+Imag[r(7)]-Imag[r(9)]+Imag[r(10)]-Imag[r(12)]-Imag[r (19)]+Imag[r(21)]-Imag[r(22)]+Imag[r(24)]+Imag[r(25)]-Imag[r(27)]-Imag[r(28)]+Imag [r(30)]}

[Equation 12] Imaginary part: Imag[r(0)]-Imag[r(2)]+Imag[r(5)]+Imag[r(8)]+Imag[r(11)]+Imag[r(13)]-Imag[r(14) ]+Imag[r(15)]-Imag[r(16)]+Imag[r(17)]-Imag[r(18)]+Imag[r(20)]+Imag[r(23)]-Imag[r( 26)]+Imag[r(29)]+ Imag[r(31)]+Imag[r(32)]+Imag[r(33)]+Imag[r(34)]+Imag[r(35)]+cos(pi/3)*{-Imag[r(1) ]-Imag[r(3)]+[mag[r(4)]+Imag[r(6)]-Iinag[r(7)]-Imag[r(9)]-Imag[r(10)]- Imag[r(12)]-Imag[r(19)]-Imag[r(21)]-Imag[r(22)]-Imag[r(24)]-Imag[r(25)]-Imag[ r(27)]+Imag[r(28)]+Imag[r(30)]}-sin(pi/3)*{-Real[r(1)]+Real[r(3)]+Real[r(4) ]-Real[r(6)]+Real[r(7)]-Real[r(9)]+Real[r(10)]-Real[r(12)]-Real[r(19)]+Real[r (21)]-Real[r(22)]+Real[r(24)]+Real[r(25)]-Real[r(27)]-Real[r(28)]+Real[r(30)]}

In the case of representing the complexity of equations 11 and 12, Equation 13 below can be obtained: [Equation 13] ((52*2) real number addition + (2*2) real multiplication) *9600 = (104 real addition + 4 real multiplication) * 9600

In the case of comparing Equation 13 with Equation 10, there is a big difference in the complexity between Equation 13 and Equation 10.

In addition, since the value "cos(pi/3)" is "1/2" (that is, cos(pi/3) = 1/2), the value "cos(pi/3) = 1/2" corresponds to the hardware. The 1-bit shift is implemented, so this value is negligible given the number of calculations. In this case, the operand can be expressed by Equation 14 below: [Equation 14] ((51*2) real addition + (1*2) real multiplication) *9600 = (102 real addition + 2 real multiplication) * 9600

In addition, the value of "sin(pi/3)" is equal to squrt(3)/2 or 0.8660 (ie sin(pi/3)=squrt(3)/2=0.8660), so the number of calculations is approximately 0.75 (=1) /2+1/4). In this case, the approximated result can be implemented with a bit shift. Therefore, if Slightly calculating the number, the complexity can be reduced as represented by Equation 15 below.

[Equation 15] ((51*2) real number addition + (1*2) real number addition) *9600 = (102 real addition) * 9600

At the same time, the positive sign "+" or the negative sign "-" can be easily implemented by the code converter, so these signs are not included in the calculation number.

The example described above is repeated twice in the time domain, thus configuring the P-SCH. However, the detailed figures are only disclosed for the purpose of illustrating the present invention, and thus the scope of the present invention is not limited to the above detailed figures and can be applied to other examples.

For example, the initial sequence can be set to a flange sequence having a length of 16. In other words, a flange sequence having a length of 16 is produced at step S1701. The flange sequence having a length of 16 is repeated four times in the time domain in step S1702. The Frank sequence is converted to a frequency domain sequence by 64 FFT at step S1703. In this case, the sequence is inserted at the interval of the four frequency index.

At step S1704, the present invention may perform a penetration procedure at the DC carrier location, or may perform sequence insertion simultaneously to avoid DC carriers. Thereafter, the sequence is converted into a time domain signal, and step S1705 is performed as needed.

In the case of using the above-described basic embodiments of the present invention and applying the specific embodiment to a Franck sequence, preferably all of the generated sequences can be generated using selected indices that satisfy the conjugated symmetry properties described above. .

By selecting an index from an index set that satisfies the conjugate symmetry properties In the case where the sequence is selected, the number of calculations can be greatly reduced in the receiving end using the cross-correlation detecting signal.

The following description relates to a specific case of a communication system in which the above-described sequence is generated/used based on the related art described above.

Aspects of communication systems for use in accordance with related art

For ease of description, the following description will be based on a frequency synchronization sequence or a time synchronization sequence (such as the primary synchronization code (PSC) for P-SCH, the sequence proposed by the specific embodiments of the present invention can be applied to the uplink preamble transmission channel (eg, RACH), any other downlink synchronization channel, signaling, control channel, and ACK/NACK communication.

Typically, the associated metering component for obtaining a time synchronization calculation program includes a delay component, as represented by (R(d)).

However, if time synchronization is not obtained, the correlation measurement caused by the delay component will not be required.

If the concept of the invention is applied to a time synchronization channel, the delay component (d) must be considered. Otherwise, if the concept of the present invention is applied to other channels that are not related to time synchronization, then the delay component (d) need not be considered.

Second, considering the delay component (d) described above, various equations have been proposed. However, it is understood by those skilled in the art that the proposed equation can be equally applied to other cases without a delay component (i.e., d = 0). Therefore, the case where there is no delay component will be omitted for convenience of description.

Next, a method for generating/using at least one sequence from a plurality of sequences will be described below, and thus the generated sequence system is used as a frequency and time synchronization sequence. That is, the sequence generation method described above does not use a single cell. A common sequence, but a particular sequence is selected from a plurality of predetermined sequences and the selected sequence is used.

A sequence for intracellular frequency and time synchronization can be referred to as a primary sequence code (PSC).

For example, if the P-SCH system uses a single common sequence design within a single cell, it has been determined that the cell common PSC system is applied to this P-SCH. Otherwise, if the P-SCH is designed using one of multiple sequences within a single cell, then a particular PSC line is selected from the multiple PSCs.

The present invention provides a method of generating a sequence from a plurality of available sequences, so that the receiving end can use only one correlation operation to calculate the correlation value between the received signal and each of the multiple sequences.

If the P-SCH is based on the Franck sequence design of Equation 6, then a sequence having a length of 16 and other sequences of length 36 can be used. In this case, if the length N is "16" and the variable "m" of Equation 6 is "4", two flange sequences are used. Similarly, if the length N is "36" and the variable "m" of Equation 6 is "6", two sequences are used. In this case, the present invention may not support three or more PSCs, causing serious problems.

The present invention provides methods for generating synchronized channel sequences that can be used in a variety of communication systems, but this method can support a variety of synchronization channels under a single cell.

There are no restrictions on the types of various communication systems described above. For ease of description, the present invention will be described based on an LTE system.

This specific embodiment will explain the Zadoff-Chu sequence by referring to Equation 16 below, so that a method for generating a complex PSC can be proposed. The The Zadoff-Chu sequence has been revealed in Equation 3.

[Equation 16] When the L system is even, When L is an odd number, k =0,1,..., L -1

In Equation 16, "m" is a natural number less than "L" and is the relative prime number of "L". For example, if L=8, "m" is set to 1, 3, 5, and 7.

This particular embodiment provides a method for generating a sequence from a complex available sequence using a Zadoff-Chu sequence. Preferably, the synchronization channel produced by the sequence according to the invention can follow the structure of Figure 10.

The sequence according to this embodiment can be generated by the procedure of Figure 16. Figure 16 is a conceptual diagram illustrating an exemplary sequence generation method in accordance with the present invention.

Referring to Fig. 16, the sequence generation method efficiently selects a sequence index from the complex sequence index (or index set) to generate a sequence at step S10. If the sequence index is selected, the sequence generation method generates a sequence in the time or frequency domain depending on the selected index at step S20. In this case, the sequence is also repeated N times in the time domain in step S30, but this step can be omitted.

The generated sequence can be mapped to the frequency resource element at step S40. Data processing for removing DC components from the frequency domain may be performed at step S51 or S52.

If the data processing for removing the DC component is performed, the data processing for converting the sequence into the time domain sequence is performed at step S60.

According to this embodiment of the invention, the method described above may also be used. Various methods are available to remove the DC component. According to the present invention, in a case where a specific component corresponding to a portion having the frequency "0" can be omitted from the frequency domain of a corresponding sequence during time domain transmission, the present invention can use any method that satisfies the above conditions. .

Second, the individual steps will be detailed below.

The step S10 for efficiently selecting a sequence index from the complex sequence index (or index set) will be detailed. In step S10, the sequence index set may include a parent sequence index or a root index, and a remaining sequence index. More specifically, if the receiving end target is time point acquisition, it is preferable that one index and the remaining sequence satisfy the condition that the interaction correlation value can be calculated by the receiving end with a smaller number of calculations. Thus, the in-body embodiment suggests that the root index set has one sequence index and the remaining sequence index meets the conditions described above.

At the same time, the number of PSCs that can be used in a cell can be determined by various methods. For example, a specific case in which a P-SCH is configured using one of 4PSCs will be described below. If only 3PSC is required and 4PSC is available, 3PSC in 4PSC can also be used as needed.

This particular embodiment can prepare 3 indexes to use the 3PSC, so the index is generated from the optional prepared root index.

Next, a method for generating the sequence using a Zadoff-Chu sequence having a length of "36" or "32" will be described below. In this case, a method for generating a P-SCH twice by repeating the sequence will be described below.

A Zadoff-Chu sequence of length 36 or 32 can be generated by Equation 16.

If the length (L) represented by Equation 16 is 36, the sequence index is indicated. The value "m" is 1, 5, 7, 11, 13, 17, 19, 23, 25, 29, 31, 33, and 35. If the length (L) is 32, the value "m" indicating the sequence index is 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, and 31.

If the length (L) is 36, one of the values 1, 5, 7, 11, 13, 17, 19, 23, 25, 29, 31, 33, and 35 is determined to be the parental sequence index. If the length (L) is 32, one of the values 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, and 31 is set as the parental sequence index. For ease of description, the parental sequence index is indicated as "m ₀ ", and the remaining sequence index is indicated by "m _i ".

In order to satisfy the conjugate symmetry property between the parent sequence index "m ₀ " and the remaining sequence index "m _i ", it is preferable to establish the relationship of Equation 17.

In Equation 17, "P _L " is a value corresponding to a single period equal to 2 * pi in the polyphase sequence. Typically, the value of the denominator of the phase component in the sequence generation equation corresponds to a value equal to a single period.

In other words, in the case of a polyphase sequence, the conjugate symmetry property described above is related to an integer multiplied by half of the sequence generation period in the sequence generation equation.

If the "k" value corresponding to the portion having the frequency "0" is omitted from the plurality of "k" values displayed in Equation 16, and then the sequence is generated, the period of the generated sequence is shorter than the normal period "1". The sequence length (L') is shorter than the sequence length (L) by "1". As a result, during the generation of the sequence, the portion having the frequency "0" is omitted from the frequency domain, and then the sequence is generated.

In order to select a root index capable of maintaining the conjugate symmetry property, the difference between the sum of the indices or the complex index may be corresponding to an integer multiplied by the associated L value instead of the L' value L/2. Thus, if the sum of the root indices corresponds to an integer value of the associated period or half of the sequence length, this means that a sequence of generation periods or sequence lengths (L) is provided when the equation is generated using a normal sequence.

Meanwhile, the following Equations 18 and 19 show an application example of Equation 17.

As shown in Equation 16, the value corresponding to a single period in the Zadoff-Chu sequence is equal to the sequence length L. Therefore, the generation period of Equation 18 is equal to "L". Equation 20 can be obtained if the same method is applied to the Frankish sequence. At the same time, the value corresponding to a single cycle is set to .

As shown in Equation 18, if the parental sequence index (m ₀ ) and the remaining sequence index (m _i ) have been determined, the receiving end can easily calculate the cross-correlation correlation value.

For example, if a single value "m ₀ " and three values (m ₁ , m _{2 ,} and m ₃ ) have been selected and a sequence is generated, the receiving end must use four sequences to calculate the cross-correlation value. That is, after receiving an unknown signal, the receiving end calculates each cross-correlation value in the sequence of m ₀ , m ₁ , m _{2 ,} and m ₃ stored in the receiving end, and must use the calculated cross-correlation value to determine whether the unknown signal is The m ₀ sequence, the m ₁ sequence, the m ₂ sequence, and the m ₃ sequence.

However, if at least one of the sequences satisfying the conjugate symmetry property is received, the present invention calculates the cross-correlation amplitude of the selected one of the sequences m ₀ to m ₃ , and thus the cross-correlation amplitude for the remaining sequence is determined. The detailed operation of the receiving end will be described below with reference to other specific embodiments.

For example, if the sequence length L is 32, the parental sequence index can be set to "1". In this case, if "1" is substituted for the m ₀ value of the first expression of Equation 18, and "32" is substituted for the "L" value, then m ₁ is equal to "15". If "1" replaces the m ₀ value of the second expression of Equation 18, and "32" replaces the "L" value, m ₂ is equal to "17". If the m ₁ and L values are replaced by the first expression of Equation 18, then m ₃ is equal to "31". In this case, the values of m ₀ , m ₁ , m ₂ and m ₃ can be determined to be a single index group.

In short, if a single parent sequence index is determined, its associated index group can also be determined.

If the length is set to 32, the values m ₀ = 3, m ₁ = 13, m ₂ = 19, and m ₃ = 29 can be determined to be a single index group. No need to rumor, other settings can be used. If 8 sequences are used, the present invention only needs to select two groups using the same method.

If the sequence length L is 36, the values m ₀ =1, m ₁ = 17, m ₂ = 19, and m ₃ = 35 can be determined to be a single index group. In addition, the values m ₀ = 5, m ₁ = 13, m ₂ = 23, and m ₃ = 31 can be determined to be a single index group.

If the L value is indicated by a prime number (i.e., L = 37), the values m ₀ =1 and m ₁ = 36 are determined to be a single group or other values m ₀ = 3 and m ₁ = 16 can be determined as a single group.

If the L value is an odd number, Equation 18 can be simplified as expressed by Equation 19 below: [Equation 19] m ₀ + m ₁ = L

If a sequence corresponding to the sequence index selected by Equation 19 is used, all related operations can be performed by a single correlation operation in the same manner as in Equation 19.

Equation 19 corresponds to a subset of Equations 17 and 18.

The selected sequence according to the invention may be a Zadoff-Chu sequence, all CAZAC sequences, or a polyphase sequence consisting of an exponential function. For example, the selected sequence can be a Frank sequence. However, if the selected sequence is determined to be a Frank sequence, Equations 18 and 19 are modified to become Equation 21 below.

Equations 20 and 21 below may also correspond to a subset of Equation 17.

[Equation 21]

The sequence selected for this particular embodiment can be a truncated Zadoff-Chu sequence as desired. In the case of generating a Zadoff-Chu sequence, the sequence length is set to a prime number, and a much more sequence can be obtained. In this case, some of the bits are truncated so that the truncated Zadoff-Chu sequence can be configured. For example, if the length L is discarded after the sequence having the length 36 is generated, a sequence of length 36 can be generated.

As can be seen from Equation 19, a two-sequence index group that is processed once can be generated. For example, if a Zadoff-Chu sequence having a length of 37 is provided, the index group or index set can be set to (1 to 36), (2 to 35), (3 to 34), (4 to 33), (5 to 32), (6 to 31), (7 to 30), (8 to 29), (9 to 28), (10 to 27), (11 to 25), (12 to 24), (13 to 24) , (14 to 23), (15 to 22), (16 to 21), (17 to 20), and (18 to 19).

Since Equation 19 is a particular format of Equation 18, the sequence index that satisfies Equation 19 corresponds to other sequence indices that satisfy Equation 18.

As described above, all sequence indices can be selected according to Equation 17, or can be selected by other methods. For example, some sequence indices are selected by Equation 17, and any of the selected sequence indices are processed by CS (cyclic shift) by a predetermined amplitude such that a new sequence can be selected based on the CS processing results.

For example, the sequence index "1" and "31" are selected, each having a length of 32. In this case, the sequence corresponding to the sequence index "1" or "31" can be CS processed by half of the sequence length so that a new sequence can be selected based on the CS processing result. In other words, having a length of 32 corresponds to the sequence index "1" Or the sequence of "31" is processed by "16" CS, so that a new third sequence can be selected according to the 16-CS processing result.

It should be noted that the numerical values described above are disclosed for illustrative purposes only, and thus the concept of the present invention is not limited to only the numerical values described above, and is applied to other examples as needed.

For convenience of description, an exemplary case in which the sequence length L is set to 32 or 36 will be described below.

If the length is set to 32, an exemplary case in which the values m ₀ =1, m ₁ = 15, m ₂ = 17, and m ₃ = 31 are set as a single index group will be described. If the length is set to 36, an exemplary case in which the values m ₀ =1, m ₁ = 17, m ₂ = 19, and m ₃ = 35 are set as a single index group will be described.

Step S20 of Fig. 16 for generating a sequence in the time or frequency domain in accordance with the selected sequence will be described below.

In the case of Equation 16, a sequence of a single index group having a length of 36 and values m ₀ =1, m ₁ = 17, m ₂ = 97, and m ₃ = 35 can be generated. Table 9 below shows examples of sequences that have been generated.

The results of Table 9 pertain to the four sequences. Any of the four sequences can be configured in the form of Figure 11. However, Figure 11 is for the Frank sequence and the results for Table 9 are for the Zadoff-Chu sequence. -

In the case of Equation 16, a sequence of associations with a single index group having a length of 32 and values m ₀ =1, m ₁ = 15, m ₂ = 17, and m ₃ = 31 can be generated. Table 10 below shows examples of sequences that have been generated.

The step S30 for repeating the sequence N times in the time domain of Fig. 16 will be described below.

Step S30 can be omitted for convenience of description, and the "N" value can be freely determined. set.

The results of Figure 9 (2x overlap structure in the real-time domain) will be described below with reference to Tables 11 and 12. Tables 11 and 12 below show the repeated results of Table 9.

An example obtained when the result of Table 10 is repeated twice in the time domain will be described below with reference to Tables 13 and 14. As can be seen from Tables 13 and 14, the results of Table 10 are repeated again.

Next, the following description will be used to map the time domain sequence to a frequency domain of a frequency domain in Fig. 16. However, it should be noted that the sequence in accordance with the present invention can be generated from the frequency domain such that it can be directly mapped to frequency resource elements as needed.

If a sequence with a 2x overlap structure is mapped to the frequency domain, a particular sequence will be generated in the frequency domain. In this case, due to the DFT operational characteristics, this particular sequence has a frequency component that is only at the even frequency index of the frequency domain.

In more detail, if the sequences of Tables 11 and 12 are mapped to the frequency domain, the following sequences shown in Tables 15 and 16 can be obtained.

If the sequences of Tables 13 and 14 are mapped to the frequency domain, the following sequences shown in Tables 18 and 17 can be obtained.

Next, the step S51 or S52 for removing the DC component from the frequency domain in Fig. 16 will be explained below.

Step S51 is for performing the penetration of the DC component. Only the DC component in Table 15 is changed to a value of zero. In other words, the results of Tables 15 and 16 are shown in Table 19 below, and the results of Tables 17 and 18 are shown in Table 20 below.

For convenience of description, the following Tables 19 and 20 indicate only the DC component, and the remaining components other than the DC component are omitted from Tables 19 and 20.

Step 51 can be based on the frequency domain interpretation described above, or also based on time domain interpretation.

For example, in accordance with this particular embodiment of the invention, a sequence having a length of 35 can be indicated by c(n). This "c(n)" sequence corresponds to the time domain sequence. The DC-through result of the "c(n)" sequence can be indicated by "d(n)".

In this case, the "c(n)" sequence can be expressed as

And the "d(n)" sequence can be expressed as:

If the sequence has a repeating structure in the time domain in step S52, a frequency component alternately appears in the frequency index of the frequency domain. At step S52, in order to prevent the frequency component from being present in the DC component during the subcarrier mapping, a corresponding sequence is shifted or CS processed to remove the DC component.

The index generated by Tables 15 to 18 is adjusted by the above step S52, and is Detailed descriptions will be omitted here for ease of description.

After the data processing for removing the DC component is completed, another data processing S60 for converting the generated sequence into a time domain sequence is performed. If the results of Table 19 are processed by the above step S60, the results of Tables 21 and 22 are obtained. If the results of Table 20 are processed, the results of Tables 23 and 24 can be obtained.

Figure 17 shows a comparison of cluster mappings between sequences that do not have a DC component and other sequences that have a DC component in accordance with the present invention.

In more detail, if the parental sequence index (m ₀ ) is "1", the 2x repeated result of the sequence having a length of 36 is shown in the 17th (a) figure, and the sequence having the length of 32 is 2x. The results are shown in Figure 17(b).

In this case, the 17th (a) and 17 (b) diagrams of the above two cases only include only 12 clusters. Although the DC runs through, the cluster position is shifted by the through value, thus maintaining 12 fixed clusters.

The feature described above with a smaller number of clusters can substantially reduce the number of computations associated with associated functions at the receiving end.

Figure 18 illustrates a conceptual diagram of a method for designing a sequence in a frequency domain, thus forming a 2x repeating structure in the time domain in accordance with the present invention.

The Zadoff-Chu sequence maintains ideal correlation characteristics in the time and frequency domains. Thus, the sequence can be generated in the time domain or can also be generated in the frequency domain.

In other words, if a Zadoff-Chu sequence is inserted into the frequency domain and the sequence is inserted into the even-numbered frequency index at intervals of two partitions (ie, two spaces), a sequence map as generated in the time domain is obtained. The same result in the case above the time domain.

An additional description of step S10 of Fig. 16 will be described below. The method for selecting a multi-sequence index is equivalent to a method of easily calculating the interactivity correlation using the receiving end.

However, the Zadoff-Chu sequence basically acts as a polyphase sequence and is therefore susceptible to frequency shifting.

Therefore, it is preferable to select the sequence under consideration of the frequency offset in the sequence selection step.

In other words, if three sequences are selected without regard to the frequency offset according to Equation 18, it may be difficult for the present invention to search for a correct correlation value based on the frequency offset. In this case, the two sequence indices in the three-sequence index can be determined by Equation 18, and the remaining sequence index can be determined taking into account the frequency offset feature.

In summary, in the case of selecting a complex sequence index, Equation 18 can only be considered, and the frequency offset feature can also be considered in conjunction with Equation 18.

The above concepts relate to complex sequence indices that take into account frequency offsets. A method for additionally considering other criteria instead of frequency offset will be described below.

Next, a method for considering a sequence index for additional consideration of related features will be described below.

For example, the Zadoff-Chu sequence acts as a CAZAC sequence, so it is preferable to select a specific sequence with ideal autocorrelation features and excellent cross-correlation features. For example, if the length is 35, the set of three sequences (1, 2, 34) or (1, 33, 34) can be selected considering equation 19, frequency offset characteristics, and PAPR features.

The cross-correlation features of the index set (1, 2, 34) are shown in Figure 19.

Next, features of a sequence having a length of 35 according to the present invention will be described hereinafter.

Preferably, a sequence having a length of 35 is available for the LTE system.

It has been assumed that the SCH signal is transferred to a six-radio block (corresponding to 73 sub-carriers including a DC component).

If the 2x repetitive structure is constructed in the time domain using 73 subcarriers, a sequence having a length of 36 can be used. All frequency or time domain conditions can be made available. For example, although the sequence is not repeated in the time domain or has been repeated three times, all conditions in the frequency domain or time domain may be made available.

In this case, the present invention requires a receiver of a (1.08 x MHz) interpolator.

However, based on the criteria described above (ie, reference), an optimal indexing group (1, 2, 35). In this case, the interaction correlation is shown in Fig. 20.

In the worst case scenario, the index group of Figure 20 can have a 40% cross-correlation.

In this case, it is preferable that the present invention can use a sequence of a shorter length than "36".

In this case, it is preferable that the present invention achieves a desired length of initial generation and simultaneously selects an odd length sequence, so that it is more preferable to set the length to 35.

A sequence having a length of 35 can search for the set having related features that are better than the even length sequence.

For reference, the selection of the sequence indices (1, 2, 34) in Figures 19 and 20 relates to the 2x repetition of the sequence.

The present invention may use a corresponding sequence when generating a PSC for P-SCH It is not necessary to repeat the sequence after the sequence is generated.

It has been hypothesized that the present invention uses a three Zadoff-Chu sequence as a multiple sequence for PSC. In this case, the present invention must select two indexes from the three Zadoff-Chu sequences, so in the case of using a sequence having a length of 63, the sum of the two indexes satisfies "63". As a result, the conjugate symmetry properties between the corresponding sequences can be satisfied.

Also, other conditions may be used to select the remaining index other than the two indices, and preferably the remaining index may be selected taking into account the frequency offset problem (and/or PAPR (CM)) described above.

Under the above assumptions, if the frequency offset sensitivity and/or the degree of PAPR for each index is expressed according to various conditions, the following results can be obtained.

Figure 21 is a diagram showing the frequency shift sensitivity and CM under various conditions in accordance with the present invention.

Referring to Fig. 21, "Nzc" is an indication of the length of the Zadoff-Chu (zc) sequence. Case 1 refers to the use of a ZC sequence having a length of 63. Case 2 refers to a ZC sequence having a length of 63 that is used in accordance with a cyclic extension scheme.

Case 3 refers to the use of a ZC sequence having a length of 64. Case 4 refers to a ZC sequence having a length of 64 that is used by a truncation scheme.

In more detail, the 21st (a) graph shows the frequency offset sensitivity of the cases 1 to 4 described above, and the 21st (b)th graph shows the CM of each of the above cases 1 to 4.

Based on the results described above, the present invention provides a method for selecting a root index set as shown in Table 25 below.

In other words, if the root index of the first sequence, the root index of the second sequence, and the root index of the third sequence are indicated by (x, y, z), then (34, 29, 25) is in case 1. The choices are made, and (34, 29, 25) are selected under Case 2, (29, 31, 27) are selected under Case 3, and (31, 34, 38) are selected under Case 4. Except for the root index set of Case 3 in these root index sets, all of these sets, each of which has the conjugate symmetry properties described above, are included in the sequence selection procedure.

When the selected root index set is used as described above, the autocorrelation curve is as follows.

Figures 22 through 25 are diagrams showing the autocorrelation curves of individual sets when an index set is selected in accordance with the present invention; in Figures 22 through 25, a 1-part correlation is indicated to indicate a frequency offset of 0.1 ppm, And the 2-part correlation indicates a frequency offset condition of 5.0 ppm. In the case where the root index set is used in accordance with the present invention, it is recognized that excellent autocorrelation features are available.

Meanwhile, a method for transmitting a signal using a sequence generated when using the root index set of Case 1 and using a ZC sequence having a length of 63 will be described hereinafter. In this case, in the root index set of Case 1, the root index of the first sequence is 34, the root index of the second sequence is 29, and the root index of the third sequence is 25.

If "34", "29" and "25" are used as the root index of the three-sequence combination, the sum of the root indexes "34" and "29" corresponds to 63 of the length of the corresponding ZC sequence, thus satisfying the above Conjugate symmetry properties. Therefore, if the sequence generated by the root index described above is transmitted as a communication signal, the receiving end can easily calculate the interaction-related operation using the generated sequence.

Meanwhile, if any of the root indices from the root index set described above is selected such that a sequence having a length of 62 is generated, a method for mapping the generated sequence to the frequency domain resource element will be described hereinafter.

Figure 26 is a conceptual diagram illustrating a method for mapping sequence to frequency domain resource elements having a length of 63 in accordance with the present invention.

After generating a sequence having a length of 63, the present invention continuously maps the generated sequence to a frequency resource element to (as far as possible) maintain a ZC sequence characteristic indicating that the ZC sequence has a fixed amplitude in the time and frequency domains, and A detailed description thereof will be described.

As can be seen from Fig. 26, in the Zadoff-Chu (ZC) sequence having a length of 63, the component corresponding to "P(0) to P(30)" is from a frequency resource having "-31". The frequency resource component of the component index is continuously mapped to the frequency resource component having the frequency resource component index of "-1", and the component corresponding to "P(32) to P(62)" is from a frequency having "1" Resource component The frequency resource element of the index is continuously mapped to the frequency resource element having the frequency resource element index of "31". In the mapping operation described above, the 32nd element (i.e., P(31)) of the generated sequence is mapped to the portion of the frequency "0".

Accordingly, this embodiment provides a method for penetrating a portion of the "P(31)" portion mapped to a portion having a frequency of "0" as shown in FIG. However, the present invention may also use another method that can penetrate a portion having a frequency of "0" during time domain transmission, as needed.

The sequence mapped to the frequency domain can be converted to a time domain signal by IFFT or equivalent operation (such as IDFT or IFT), so it can also be transmitted as an OFDM symbol signal.

The signal transmitted by the above specific embodiment can be received at the receiving end, so that the receiving end can detect a corresponding signal by using an inter-related operation. In this case, in the case of using a sequence set having the above-described conjugate symmetry property, the receiving end can more easily detect the signal.

Next, the signal detection procedure at the receiving end (i.e., the method for calculating the interactive correlation value) will be described below.

Aspect of the receiving end

The operation of the aspect of the receiving end will be described hereinafter.

There is a predetermined rule in the Tx sequence generated by the specific embodiment described above. Therefore, the receiving end can obtain the correlation value of the sequence corresponding to the remaining root sequence index by using a correlation value corresponding to a specific sequence of a single root sequence index, instead of calculating the interaction correlation value of all the sequences.

A method for calculating an interaction correlation value in accordance with this particular embodiment will be described below. This particular embodiment calculates the cross-correlation values between the Rx signals and the sequences of the multiple sequences. In this case, the present invention determines when the calculation is A number of intermediate values resulting from the correlation between the Rx signal and a particular sequence (ie, the first sequence). Moreover, the present invention can calculate not only the cross-correlation value between the Rx signal and the first sequence but also another cross-correlation value between the Rx signal and the other sequence (ie, the second sequence) by adding or subtracting the intermediate values.

Various cases in which multiple available sequences are selected are detailed below.

<Case 1>

This example shows a method for calculating the cross-correlation values of the selected sequences having a length of 36 and values m ₀ =1, m ₁ = 17, m ₂ = 19, m ₃ 35.

The receiving end stores a sequence with a sequence index of "1" and calculates an interaction correlation value between the stored sequence and the received sequence. In this case, in the case where an intermediate result generated when calculating the cross-correlation value between the Rx signal and the sequence having the sequence index "1" is used, the Rx signal and the sequence having the sequence index "17" can be calculated. The cross-correlation value can be used to calculate the cross-correlation value between the Rx signal and the sequence with the sequence index "19", and at the same time calculate the cross-correlation value between the Rx signal and the sequence with the sequence index "35".

This example will be described based on a specific case where the cross-correlation value of the τth delay is calculated. In other words, if the Rx signal is indicated by r ( n ), then this instance will be described based on the cross-correlation value associated with the dth delay sample r ( n + d ).

In this case, the result of the correlation value of the sequence index "m" is shown in Equation 22 below:

Where m ₀ =1, m ₁ =17, m ₂ =19 and m ₃ =35, so the following relationship can be provided.

Further, a ^{m1 = 17} ( k ) is an indication of the common axis of a ^{m0 = 1} ( k ) under the condition that the "k" value is even. If the value of "k" is an odd number, the real part of a ^m0=1 ( k ) is replaced by its imaginary part, and the result of the substitution value is multiplied by the value "-1".

Similarly, a ^{m2 = 19} ( k ) is an indication of the conjugate of a ^{m0 = 1} ( k ) under the condition that the "k" value is even. If the "k" value is an odd number, a ^m2=19 ( k ) is an indication of the result obtained when the real part is replaced by an imaginary part.

a ^m3=35 ( k ) is obtained when the value of "k" is evenly multiplied by the real part of a ^m0=1 ( k ) when the "k" value is an even number. If the "k" value is an odd number, a ^m3-35 ( k ) is equal to the conjugate symmetry property of α ^{m0 = 1} ( k ).

The Rx signal r(k+d) can be calculated using an instantaneous correlation value of each sequence associated with "r_i(k+d)+jr_q(k+d)". In this case, "r_i()" is an indication of the real part of the Rx signal, and "r_q()" is an indication of the imaginary part of the Rx signal.

For ease of description, the cross-correlation value of the Rx signal (ie, the cross-correlation value between the Rx signal and the known sequence at the receiving end) can be defined as follows.

For convenience of description, the correlation between the known sequence at the receiving end and the even sequence of the Rx signal Σ r (2 l + d ) ( a ^{m0 = 1} (2 l )) ^* is divided into a real part and an imaginary part. , as expressed in Equation 24 below:

The result of Equation 24 can be divided into a real part (hereinafter referred to as "Reven(0)") and an imaginary part (hereinafter referred to as "Ieven(0)").

If the cross-correlation value of the odd-numbered sequence of the associated Rx signal is divided into a real part and an imaginary part, Equation 25 below can be obtained:

The result of Equation 25 can be divided into a real part (hereinafter referred to as "Rodd (0)") And an imaginary part (hereinafter referred to as "Iodd(0)").

If the cross-correlation value Σ r (2 l + d ) ( a ^{m0 = 1} (2 l )) of the even-numbered sequence of the conjugate of the associated Rx signal is divided into a real part and an imaginary part, the following equation 26 can be obtained:

The result of Equation 26 can be divided into a real part (hereinafter referred to as "Reven (1)") and an imaginary part (hereinafter referred to as "Ieven (1)").

If the cross-correlation value Σ r (2 l +1+ d ) ( a ^m0=1 (2 l +1)) of the conjugated odd-numbered sequence of the associated Rx signal is divided into a real part and an imaginary part, the following equation 27 can be obtained:

The result of Equation 27 can be divided into a real part (hereinafter referred to as "Rodd (1)") and an imaginary part (hereinafter referred to as "Iodd (1)").

In this case, the calculation of the values "Reven0", "Ieven0", "Rodd0", "Iodd0", "Reven1", "Ieven1", "Rodd1", and "Iodd1" can be regarded as equal to those shown in Equations 24 to 27. The calculation of the values "Reven_i_i", "Revenq_q", "Ieven_i_q", "Ieven_q_i", "Rodd_i_i", "Rodd_q_q", "Iodd_i_q" and "Iodd_q_i".

Hereinafter, a method for calculating the above-described values "Reven_i_i", "Revenq_q", "Ieven_i_q", "Ieven_q_i", "Rodd_i_i", "Rodd_q_q", "Iodd_i_q", and "Iodd_q_i" will be described with reference to Equation 28 below:

The procedure of Equation 28 can be calculated by approximation. In other words, the calculation of Equation 28 can be easily implemented by quantization.

For example, it is preferable that the above approximation can be performed in the following form: 0.93969→1, 0.17365→0.125 (=1/8), 0.76604→0.75 (=1/2+1/4), 0.34202→0.375 (=1/4+1/8), 0.98481→1, 0.64279→0.625 (=1/2+1/8), 0.99619→1, 0.70711→0.75 (=1/2+1/4), 0.57358→0.625 (=1/2+1/8), 0.42262→0.375 (=1 /4+1/8), 0.087156→0.125 (=1/8), 0.81915→0.875 (=1-1/8), and 0.90631-→0.875 (=1-1/8).

If the concept of Equation 28 is approximated, Equation 29 below can be obtained:

In this case, it should be noted that the result of Equation 29 is generated by a single known sequence of the receiving end (i.e., a sequence corresponding to the parental sequence index) and the Rx signal. Although the receiving end must perform the correlation operation associated with all four PSCs under the condition that one of the cells transmits four PSCs, the receiving end uses only a sequence corresponding to the parental sequence index to calculate the value of Equation 29. Likewise, the cross correlation values for all four PSCs can be calculated using the values of Equation 29.

One method for calculating the correlation value associated with all four PSCs using the results of Equation 29 is as follows.

[Equation 31]

Equation 30 is an indication of an inter-correlation value between a sequence corresponding to the parent sequence index (m ₀ ) and the Rx signal. Equation 31 is an indication of the inter-correlation value between the sequence corresponding to the remaining sequence index (m ₁ ) and the Rx signal. Equation 32 is an indication of an inter-correlation value between a sequence corresponding to the remaining sequence index (m ₂ ) and the Rx signal. Equation 33 indicates a line in the cross-correlation between the values of the remaining sequence index (m ₃₎ and the Rx signal sequence.

In short, if the multiple sequence is generated according to the method of the present invention in the specific embodiment described above, the present invention can calculate the multiple sequence corresponding to the multiple sequence index by using both the sequence corresponding to a single sequence index and the Rx signal. Interaction related values.

Figure 27 is a block diagram showing the structure of the receiving end in accordance with the present invention.

Referring to Figure 27, the Rx signal at the receiving end and the known sequence at the receiving end are applied to the index demapper 1900. The unit 1950 at the receiving end of Fig. 27 can calculate "Reven_i_i", "Revenq_q", "Ieven_i_q", "Ieven_q_i", "Rodd_i_i", "Rodd_q_q", "Iodd_i_q" and "Iodd_q_i" using Equation 29 or 29.

The values "Reven_i_i", "Revenq_q", "Ieven_i_q", "Ieven_q_i", "Rodd_i_i", "Rodd_q_q", "Iodd_i_q", and "Iodd_q_i" are calculated as "Reven0", "Ieven0", "" using Equations 24 to 27, respectively. Rodd0", "Iodd0", "Reven1", "Ieven1", "Rodd1" and "Iodd1".

For example, "Reven_i_i+Revenq_q" is calculated as "Reven ⁰ " and "-Ieven_i_q+Ieven_q_i" is calculated as "Ieven ⁰ ".

The operation of equations 24 through 27 is performed by unit 1960.

If the addition or subtraction of Equations 30 to 33 is applied to the results of 1960 units of Reven0, Ieven0, Rodd0, Iodd0, Reven1, Ieven1, Rodd1, and Iodd1, the individual sequence indices (m ₀ , m ₁ , m ₂ , Four correlation values for m ₃ ).

For example, the correlation value of the m ₀ value is calculated by Equation 30. More specifically, the sum of Reven ⁰ and Rodd ⁰ is used as the real part of the correlation value of the m ₀ value, and the sum of Ieven ⁰ and Iodd ⁰ is used as the imaginary part of the m ₀ value.

Referring to Equations 24 to 33 and Figure 27, although the "1960" unit does not exist alone, the final result can be obtained by the result of 1850 units, and it can be recognized that the final result can only use the "1960" unit instead of the "1950" unit. Obtain.

The concept of Figure 27 will be described below with reference to another aspect, and a detailed description thereof.

In the case of calculating the cross-correlation value between the Rx signal and the sequence corresponding to the "m ₀ " value, if the real part of the cross-correlation value associated with the even-numbered "m ₀ " sequence is set to a first result, then the first The result can be indicated by Reven ⁰ according to Equation 24. In Fig. 27, reference numeral "1901" of Fig. 27 indicates the first result.

If the imaginary part of the cross-correlation value associated with the even-numbered "m ₀ " sequence is set to a second result, the second result may be indicated by Ieven ⁰ according to Equation 24. In Fig. 27, the reference numeral "1902" of Fig. 27 indicates the second result.

If the real part of the cross-correlation value associated with the odd-numbered "m ₀ " sequence is set to a third result, the third result may be indicated by Rodd ⁰ according to Equation 25. In Fig. 27, reference numeral "1903" of Fig. 27 indicates the first result.

If the imaginary part of the cross-correlation value associated with the odd-numbered "m ₀ " sequence is set to a fourth result, the fourth result may be indicated by Iodd ⁰ according to Equation 25. In Fig. 27, the reference numeral "1904" in Fig. 27 indicates the fourth result.

If the real part of the cross-correlation value of the conjugate of the even-numbered "m ₀ " sequence is set to a fifth result, the fifth result can be indicated by Reven ¹ according to Equation 26. In Fig. 27, the reference numeral "1905" of Fig. 27 indicates the fifth result.

If the imaginary part of the cross-correlation value of the conjugate of the even-numbered "m ₀ " sequence is set to a sixth result, the sixth result may be indicated by Ieven ¹ according to Equation 26. In Fig. 27, the reference numeral "1906" of Fig. 27 indicates the sixth result.

If the real part of the cross-correlation value of the conjugate of the odd-numbered "m ₀ " sequence is set to a seventh result, the seventh result can be indicated by Rodd ¹ according to Equation 27. In Fig. 27, the reference numeral "1907" in Fig. 27 indicates the seventh result.

If the real part of the cross-correlation value of the conjugate of the odd-numbered "m ₀ " sequence is set to an eighth result, the eighth result can be indicated by Iodd ¹ according to Equation 27. In Fig. 27, the reference number "1908" of Fig. 27 indicates the eighth result.

According to the method described above, the first to eighth results are determined. If the two results of the eight results described above are added or subtracted from each other, the calculated value of the "1970" unit is obtained.

For example, the real part of the correlation value of the "m ₀ " sequence is equal to the sum of the "1901" unit and the "1903" unit. The imaginary part of the correlation value of the "m ₀ " sequence is equal to the sum of the "1906" unit and the "1906" unit.

In short, the receiving end calculates the first to eighth results described above, and can perform addition or subtraction between two different results from the first to eighth results, so that the "m ₀ to m ₃ " sequence can be calculated. Interaction-related values.

Figure 27 shows a specific case where the sequence length is indicated by an even number. Those skilled in the art understand that the concepts described above can be applied not only to even numbers but also to Applied to odd numbers.

Next, a receiver of a peculiar length sequence will be described hereinafter with reference to Fig. 18 and Equation 18 below.

First, if the sequence length is 35, then two sequence indices can be selected.

For example, the length of the parent sequence index can be set to "1", and the length of the remaining sequence index is set to "34".

In this case, the expression corresponding to Equation 23 is expressed by the following Equation 34:

In this case, the cross-correlation value can be expressed by Equation 35 below:

To succinctly represent the result of Equation 35, the variables shown in Equation 36 below are defined as follows:

Based on Equation 36 above, the result of Equation 35 can be expressed by Equation 37 below:

An exemplary receiving end system for calculating Equation 37 is shown in Figure 28.

In Fig. 28, the four variables are calculated by Equation 36, so the correlation values of the odd-length sequences are calculated at one time. Therefore, in the case of using the above-described structure, the present invention can correctly handle the reception of a sequence having a length of 63.

As described above, a receiving end associated with a sequence of various lengths can be designed.

<Case 2>

This example shows a method for calculating the cross-correlation values of the selected sequences having a length of 36 and values m ₀ =1, m ₁ = 15, m ₂ = 17, m ₃ =32.

This particular embodiment of Case 2 will show the detailed equations, as Case 1 has described the detailed method. Further, it can be recognized which of the programs shown in FIG. 1 is regarded as a program equivalent to the case 2.

As is well known to those skilled in the art, Case 2 and a method for receiving various sequence indices can be implemented based on the interpretation of Case 1.

Equation 38 is equal to Equation 22.

When k is even otherwise

Equation 39 is equal to Equation 23.

Equation 40 corresponds to Equation 24.

Equation 41 corresponds to Equation 25.

Equation 42 corresponds to Equation 26.

Equation 43 corresponds to Equation 27.

Equation 44 corresponds to Equation 28.

Equation 45 corresponds to Equation 29.

Equation 46 corresponds to Equation 30.

[Equation 47]

Equation 47 corresponds to Equation 31.

Equation 48 corresponds to Equation 32.

Equation 49 corresponds to Equation 33.

This particular embodiment can greatly reduce the number of calculations, and a detailed description thereof will be described below.

In order to calculate the d-th correlation value of the associated PSC sequence (which has a length of L=36 and is divided into four types), the conventional method requires 575 real multiplication and 568 real addition under the assumption that the calculation by the symbol converter is ignored. .

However, the present invention requires 28 real value multiplications and 140 real value additions. In the case of quantization, the present invention does not require real multiplication, 156 real value increase, and 54 bit shift operation.

When the hardware is implemented, the symbol converter and the bit shift operation are not included in the number of calculations, so the number of calculations of each technique is shown in Table 20 below. The present invention can calculate cross-correlation values using only the four PSC sequences of 156 real-valued additions.

Also, if the length (L) is set to 32, a difference between the prior art and the performance of the present invention is produced, as shown in Table 27 below:

It is to be noted that most of the terms disclosed in the present invention are defined in consideration of the function of the present invention, and may be determined differently according to the intention of the person skilled in the art and the usual implementation method. Therefore, it is preferable that the above terms are understood based on all the contents disclosed in the present invention.

A person skilled in the art will appreciate that various modifications and changes can be made in the present invention without departing from the spirit and scope of the invention. Accordingly, the present invention is intended to cover such modifications and alternatives

The sequence produced by the present invention maintains at least a predetermined level of correlation features in the time domain and has low PAPR characteristics. Moreover, by using a sequence generated by an embodiment of the present invention, the receiving end can easily detect the sequence by the associated operation.

The present invention can configure an excellent performance channel under the condition that the sequence system is applied to a communication standard such as an LTE system.

As can be appreciated from the above, the sequences produced by the present invention maintain correlation features that are more than a predetermined level and have low PAPR characteristics.

If the sequence proposed by the present invention is applied to a communication standard such as an LTE system, a channel with excellent performance can be configured.

While the invention has been described with respect to the specific embodiments of the present invention, it will be understood by those skilled in the art that various modifications, additions and substitutions are possible without departing from the spirit and scope of the invention.

501‧‧‧ Input data

502‧‧‧channel coding unit

504‧‧‧ mapping unit

505‧‧‧IFFT

506‧‧‧ filter

507‧‧‧DAC/digital to analog converter

1900‧‧Demapper

1950‧‧‧ Receiver unit

Unit 1960‧‧

The accompanying drawings of the present invention are provided to illustrate the invention The embodiments are further described, and together with the description, illustrate the principles of the invention.

In the drawings: FIG. 1 is a structural diagram of a downlink subframe under the IEEE 802.16 system; FIG. 2 is a diagram showing the group of subcarriers transmitted from the 0th sector of the IEEE 802.16 system; FIG. 3 and FIG. A conceptual diagram illustrating various methods of including a P-SCH and an S-SCH in a radio frame; FIG. 5 is a block diagram showing a transmission/reception end for implementing an embodiment of the present invention; A method for maintaining a reasonably relevant feature in accordance with the present invention, and a flow chart for a method for designing a low PAPR sequence; FIG. 7 is an autocorrelation feature of a CAZAC sequence in accordance with the present invention; A conceptual diagram of a method for constructing a P-SCH in accordance with the present invention; FIG. 9 is a flow chart illustrating a method for generating a P-SCH in accordance with the present invention; and FIG. 10 is a diagram illustrating an exemplary secondary carrier in accordance with the present invention. Concept map in which each sub-carrier is mapped to P-SCH based on the LTE standard; Figure 11 is a block diagram showing a Franck sequence having a length of 36 in the time domain according to the present invention; and FIG. 12 illustrates the time domain 2x repeated block diagram of the structure, so that there are 72 Length sequences are generated according to the invention is formed; FIG. 13 shows the results of the step according to Fig. 9 of the present invention to S1703; Figure 14 shows the result of step S1704-1 according to Fig. 9 of the present invention; Figure 15 shows the result of the cyclic shift to the right of the result according to Fig. 13 of the present invention; and Fig. 16 is a view showing the present invention according to the present invention. A conceptual diagram of a sequence generation method; FIG. 17 shows a comparison in a cluster map between a sequence having no DC component and other sequences having a DC component in accordance with the present invention; and FIG. 18 is a diagram illustrating an on-frequency in accordance with the present invention. Designing a sequence in the domain such that a 2x overlapping structure is formed in the time domain. Figures 19 and 20 illustrate a graph of the cross-correlation features of the set of indices (1, 2, 34) in accordance with the present invention; Frequency offset sensitivity and CM pattern under various conditions of the present invention; Figures 22 through 25 are graphs of autocorrelation curves of individual sets when an index set is selected in accordance with the present invention; Figure 26 illustrates a A conceptual diagram of a method for mapping a sequence having a length of 63 to a frequency domain resource element in accordance with the present invention; and FIGS. 27 and 28 are block diagrams illustrating a receiving end in accordance with the present invention.

Representative figure without components

Claims (46)

A method for transmitting a signal to a receiver at a transmitter in accordance with an orthogonal frequency division multiplexing (OFDM) scheme in a mobile communication system, the method comprising the steps of: mapping a sequence to a frequency domain resource component, wherein The sequence is generated in a frequency domain from a specific Constant Amplitude Zero Auto-Correlation (CAZAC) sequence having a root index included in a root-index set. In one of the following, the root index set includes a first index and a second index, wherein a sum of the first and a second index corresponds to a length of the specific CAZAC sequence; converting the frequency domain map sequence into a time domain Transmitting a signal; and transmitting the time domain transmission signal to the receiver. The method of claim 1, wherein the sequence is generated from a Zadoff-Chu sequence having an odd length, and a program for generating the sequence from the Zadoff-Chu sequence is represented by the following equation: Wherein the length of the Zadoff-Chu sequence is "N", "M" is one of the root indices of the Zadoff-Chu sequence, and "n" is an index of each of the constituent components of the generated sequence, and the The sum of an index and the second index is "N". The method of claim 2, wherein the "N" is 63, and the first index and the second index are 34 and 29, respectively. The method of claim 1, wherein the root index set comprises three indexes. The method of claim 4, wherein the root index set includes 34, 29, and 25 as the first index, the second index, and a third index. The method of claim 1, wherein the transmitter uses the generated sequence as a P-SCH (primary SCH) transmission sequence. The method of claim 1, wherein the transmitter uses the generated sequence as an uplink preamble transmission sequence. A transmitter for transmitting a signal to a receiver according to an orthogonal frequency division multiplexing (OFDM) scheme in a mobile communication system, the transmitter comprising: a mapping unit adapted to map a sequence to a frequency domain resource component, wherein The sequence is generated in a frequency domain from a specific Constant Amplitude Zero Auto-Correlation (CAZAC) sequence having a root index included in a root-index set. In one case, the root index set contains one a first index and a second index, wherein the sum of the first and a second index corresponds to a length of the specific CAZAC sequence; the IFFT module is adapted to convert the frequency domain mapping sequence into a time domain transmission signal; and the radio A frequency (RF) unit adapted to transmit the time domain transmission signal to the receiver. The transmitter of claim 8, wherein: the sequence is generated from a Zadoff-Chu sequence having an odd length, and a program for generating the sequence from the Zadoff-Chu sequence is represented by the following equation Indicates: Wherein the length of the Zadoff-Chu sequence is "N", "M" is one of the root indices of the Zadoff-Chu sequence, and "n" is an index of each of the constituent components of the generated sequence, and the The sum of an index and the second index is "N". The transmitter of claim 9, wherein "N" is 63, and the first index and the second index are 34 and 29, respectively. The transmitter of claim 8, wherein the root index set includes three indexes. The transmitter of claim 11, wherein the root index set includes 34, 29, and 25 as the first index, the second index, and a third index. The transmitter of claim 8, wherein the transmitter uses the generation sequence as a P-SCH (primary SCH) transmission sequence. The transmitter of claim 8 wherein the transmitter uses the generated sequence as an uplink preamble sequence. A method for detecting a sequence used in a receive (Rx) signal in accordance with an orthogonal frequency division multiplexing (OFDM) scheme in a mobile communication system, the method comprising the steps of: receiving from a transmitter The Rx signal; and detecting a sequence used in the Rx signal, wherein the frequency is generated in the Rx signal from a specific Constant Amplitude Zero Auto-Correlation (CAZAC) sequence in a frequency domain a sequence, the CAZAC sequence having one of a root index included in a root-index set, the root index set including a first and a second index, wherein the first and a second index And corresponds to one of the lengths of the particular CAZAC sequence. The method of claim 15, wherein the sequence used in the Rx signal is generated from a Zadoff-Chu sequence having an odd length, and a program for generating the sequence from the Zadoff-Chu sequence. It is represented by the following equation: Wherein the length of the Zadoff-Chu sequence is "N", "M" is one of the root indices of the Zadoff-Chu sequence, and "n" is an index of each of the constituent components of the generated sequence, and the The sum of an index and the second index is "N". The method of claim 16, wherein the "N" is 63, and the first index and the second index are 34 and 29, respectively. The method of claim 15, wherein the root index set comprises three indexes. The method of claim 18, wherein the root index set includes 34, 29, and 25 as the first index, the second index, and a third index. The method of claim 15, wherein the Rx signal is a P-SCH (primary SCH) signal. The method of claim 20, further comprising the step of: synchronizing with the transmitter according to the detection of the sequence used in the Rx signal. A receiver for detecting a sequence used in a receive (Rx) signal in accordance with an orthogonal frequency division multiplexing (OFDM) scheme in a mobile communication system, the receiver comprising: a radio frequency (RF) unit, adapted Receiving the Rx signal from a transmitter; and an index demapper adapted to detect a sequence used in the Rx signal, wherein a specific fixed amplitude zero autocorrelation in a frequency domain (Constant Amplitude Zero Auto- Correlation, CAZAC) sequence generates a sequence used in the Rx signal, the specific CAZAC sequence having one of a root index included in a root-index set, the root index set including a first a second index, wherein the sum of the first and a second index corresponds to a length of the particular CAZAC sequence. The receiver of claim 22, wherein the sequence used in the Rx signal is generated from a Zadoff-Chu sequence having an odd length, and one of the sequences used to generate the sequence from the Zadoff-Chu sequence The equation is expressed by the following equation: Wherein the length of the Zadoff-Chu sequence is "N", "M" is one of the root indices of the Zadoff-Chu sequence, and "n" is an index of each of the constituent components of the generated sequence, and the first of The sum of the index and the second index is "N". The receiver of claim 23, wherein "N" is 63, and the first index and the second index are 34 and 29, respectively. The receiver of claim 22, wherein the root index set includes three indexes. The receiver of claim 25, wherein the root index set includes 34, 29, and 25 as the first index, the second index, and a third index. The receiver of claim 22, wherein the Rx signal is a P-SCH (primary SCH) signal. The receiver of claim 22, wherein the receiver performs the transmission according to the detection of the sequence used in the Rx signal. Synchronization of the transmitter. A method for transmitting a signal to a receiver using a Constant Amplitude Zero Auto-Correlation (CAZAC) sequence at a transmitter, the method comprising the steps of: continuously mapping a sequence to a frequency resource element; Converting the frequency domain mapping sequence into a time domain transmission signal; and transmitting the time domain transmission signal to the receiver, wherein the sequence to be mapped to the frequency resource elements is generated in a frequency domain from a CAZAC sequence according to an index, The sequence generated therein does not have a component corresponding to a central component of the CAZAC sequence in the frequency domain. The method of claim 29, wherein the sequence is generated by a central component of the CAZAC sequence from the CAZAC sequence in the frequency domain. The method of claim 29, wherein the CAZAC sequence has an odd length Zadoff-Chu sequence, wherein a program for generating the Zadoff-Chu sequence is represented by the following equation: The length of the Zadoff-Chu sequence is "N", "M" is an index of one of the Zadoff-Chu sequences, and "n" is an index of each of the constituent components of a particular Zadoff-Chu sequence. The method of claim 31, wherein the length of the Zadoff-Chu sequence is 63, and wherein the frequency resource element having a frequency resource element index of "-31" starts to have a "-1" The frequency resource element of the frequency resource element index continuously maps the constituent components of the Zadoff-Chu sequence corresponding to the "n" value of "0 to 30" to the frequency resource element, and one frequency having a "1" The frequency resource element of the resource element index starts to a frequency resource element having a frequency resource element index of "31", and continuously maps the constituent components of the Zadoff-Chu sequence corresponding to the "n" value of "32 to 62" to the frequency. Resource component. The method of claim 29, wherein the generating sequence is a P-SCH (primary SCH) transmission sequence. A transmitter for transmitting a signal to a receiver using a Constant Amplitude Zero Auto-Correlation (CAZAC) sequence, the transmitter comprising: a mapping unit adapted to continuously map a sequence to a frequency resource element; An IFFT module adapted to convert the frequency domain mapping sequence into a time domain transmission signal; and a radio frequency (RF) unit adapted to transmit the time domain transmission signal to the a receiver, wherein the sequence to be mapped to the frequency resource elements is generated in a frequency domain from a CAZAC sequence according to an index, wherein the sequence generated does not have a center corresponding to one of the CAZAC sequences in the frequency domain The weight of the component. The transmitter of claim 34, wherein the central component of the CAZAC sequence from the CAZAC sequence is generated in the frequency domain to generate the sequence. The transmitter of claim 34, wherein the CAZAC sequence has an odd length Zadoff-Chu sequence, wherein a program for generating the Zadoff-Chu sequence is represented by the following equation: The length of the Zadoff-Chu sequence is "N", "M" is an index of one of the Zadoff-Chu sequences, and "n" is an index of each of the constituent components of a specific Zadoff-Chu sequence. The transmitter of claim 36, wherein the length of the Zadoff-Chu sequence is 63, and wherein a frequency resource element having a frequency resource element index of "-31" begins with a "-" 1" frequency resource component index frequency The source element continuously maps the constituent components of the Zadoff-Chu sequence corresponding to the "n" value of "0 to 30" to the frequency resource element, and starts with a frequency resource element having a frequency resource element index of "1" The frequency resource element having the frequency resource element index of "31" continuously maps the constituent components of the Zadoff-Chu sequence corresponding to the "n" value of "32 to 62" to the frequency resource element. The transmitter of claim 34, wherein the generated sequence is a P-SCH (primary SCH) transmission sequence. A method for receiving a signal from a transmitter using a Constant Amplitude Zero Auto-Correlation (CAZAC) sequence at a receiver, the method comprising the steps of: receiving a signal from the transmitter; and detecting the A sequence is used in the received signal, wherein the sequence used in the received signal does not have a component corresponding to a central component of the CAZAC sequence in the frequency domain. The method of claim 39, wherein the CAZAC sequence has an odd length Zadoff-Chu sequence, wherein a program for generating the Zadoff-Chu sequence is represented by the following equation: The length of the Zadoff-Chu sequence is "N", "M" is an index of one of the Zadoff-Chu sequences, and "n" is an index of each of the constituent components of a particular Zadoff-Chu sequence. The method of claim 40, wherein the length of the Zadoff-Chu sequence is 63, and wherein the frequency resource element having a frequency resource element index of "-31" starts to have a "-1" The frequency resource element of the frequency resource element index continuously maps the constituent components of the Zadoff-Chu sequence corresponding to the "n" value of "0 to 30" to the frequency resource element, and one frequency having a "1" The frequency resource element of the resource element index starts to a frequency resource element having a frequency resource element index of "31", and continuously maps the constituent components of the Zadoff-Chu sequence corresponding to the "n" value of "32 to 62" to the frequency. Resource component. The method of claim 39, wherein the sequence used in the received signal is a P-SCH (primary SCH) transmission sequence. A receiver for receiving a signal from a transmitter using a Constant Amplitude Zero Auto-Correlation (CAZAC) sequence, the receiver comprising: a radio frequency (RF) unit adapted to receive from the transmitter a signal; and an index demapper adapted to detect a sequence used in the received signal, wherein the sequence used in the received signal does not have a frequency corresponding to the frequency A component of one of the central components of the CAZAC sequence in the domain. The receiver of claim 43, wherein the CAZAC sequence has an odd length Zadoff-Chu sequence, wherein a program for generating the Zadoff-Chu sequence is represented by the following equation: The length of the Zadoff-Chu sequence is "N", "M" is an index of one of the Zadoff-Chu sequences, and "n" is an index of each of the constituent components of a particular Zadoff-Chu sequence. The receiver of claim 44, wherein the length of the Zadoff-Chu sequence is 63, and wherein a frequency resource element having a frequency resource element index of "-31" begins with a "-" The frequency resource element of the frequency resource element index of 1" continuously maps the constituent components of the Zadoff-Chu sequence corresponding to the "n" value of "0 to 30" to the frequency resource element, and one of the ones having "1" The frequency resource element of the frequency resource element index starts to a frequency resource element having a frequency resource element index of "31", and continuously maps the constituent components of the Zadoff-Chu sequence corresponding to the "n" value of "32 to 62" to Frequency resource component. The receiver according to claim 43 of the patent application, wherein the received signal The sequence used in the number is a P-SCH (primary SCH) transmission sequence.